Methods and systems for flight control configured for use in an electric aircraft

ABSTRACT

A system for flight control configured for use in an electric aircraft includes a sensor configured to capture an input datum. The system includes an inertial measurement unit (IMU) and configured to detect an aircraft angle and an aircraft angle rate. The system includes a flight controller including an outer loop controller configured to receive the input datum from the sensor, receive the aircraft angle from the IMU, and generate a rate setpoint as a function of the input datum. The system includes an inner loop controller configured to receive the aircraft angle rate, receive the rate setpoint from the outer loop controller, and generate a moment datum as a function of the rate setpoint. The system includes a mixer configured to receive the moment datum, perform a torque allocation as a function of the moment datum, and generate a motor command datum as a function of the torque allocation.

FIELD OF THE INVENTION

The present invention generally relates to the field of electricaircraft control. In particular, the present invention is directed tomethods and systems for flight control configured for use in an electricaircraft.

BACKGROUND

In electrically propelled vehicles, such as an electric vertical takeoffand landing (eVTOL) aircraft, it is essential to maintain the integrityof the aircraft until safe landing. In some flights, a component of theaircraft may experience a malfunction or failure which will put theaircraft in an unsafe mode which will compromise the safety of theaircraft, passengers and onboard cargo.

SUMMARY OF THE DISCLOSURE

In an aspect, a system for flight control configured for use in electricaircraft includes at least a sensor, at least a sensor configured tocapture at least an input datum from a pilot, an inertial measurementunit, the inertial measurement unit configured to detect at least anaircraft angle and detect at least an aircraft angle rate. The systemincludes a flight controller including: an outer loop controllerconfigured to: receive at least an input datum from at least a sensor,receive at least an aircraft angle from the inertial measurement unit,and generate a rate setpoint as a function of at least an input datum.The system includes an inner loop controller configured to: receive atleast an aircraft angle rate, receive the rate setpoint from the outerloop controller, and generate a moment datum as a function of the ratesetpoint. The system includes a mixer, the mixer configured to: receivethe moment datum, perform a torque allocation as a function of themoment datum, and generate at least a motor command datum as a functionof the torque allocation.

In another aspect, a method of flight control configured for use inelectric aircraft includes capturing, at an at least a sensor, an inputdatum from a pilot, detecting, at the inertial measurement unit, atleast an aircraft angle, detecting, at the inertial measurement unit, atleast an aircraft angle rate, receiving, at the outer loop controller,at least an input datum from at least a sensor, receiving, at the outerloop controller, at least an aircraft angle from the inertialmeasurement unit, generating, at the outer loop controller, a ratesetpoint as a function of at least an input datum, receiving, at theinner loop controller, at least an aircraft angle rate from the inertialmeasurement unit, receiving, at the inner loop controller, the ratesetpoint from the outer loop controller, generating, at the inner loopcontroller, a moment datum as a function of the rate setpoint,receiving, at a mixer, the moment datum, perform, at the mixer, a torqueallocation as a function of the moment datum, and generating, at themixer, at least a motor command datum as a function of the torqueallocation.

These and other aspects and features of non-limiting embodiments of thepresent invention will become apparent to those skilled in the art uponreview of the following description of specific non-limiting embodimentsof the invention in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of illustrating the invention, the drawings show aspectsof one or more embodiments of the invention. However, it should beunderstood that the present invention is not limited to the precisearrangements and instrumentalities shown in the drawings, wherein:

FIG. 1 is an illustrative embodiment of a system for flight controlconfigured for use in embodiments of the present invention;

FIG. 2 is an illustrative embodiment of an outer loop controller for usein embodiments of the present invention;

FIG. 3 is an illustrative embodiment of an inner loop controller for usein embodiments of the present invention;

FIG. 4 is an exemplary method of an aircraft control configured for usein electric aircraft in block diagram form;

FIG. 5 is a block diagram of an exemplary embodiment of a machinelearning module;

FIG. 6 is an illustration of an exemplary embodiment of an electricaircraft; and

FIG. 7 is a block diagram of a computing system that can be used toimplement any one or more of the methodologies disclosed herein and anyone or more portions thereof.

The drawings are not necessarily to scale and may be illustrated byphantom lines, diagrammatic representations and fragmentary views. Incertain instances, details that are not necessary for an understandingof the embodiments or that render other details difficult to perceivemay have been omitted.

DETAILED DESCRIPTION

At a high level, aspects of the present disclosure are directed a systemfor flight control configured for use in electric aircraft. System forflight control includes a sensor configured to capture an input datumfrom a pilot's interaction with a pilot control consistent with theentirety of this disclosure. The system includes an inertial measurementunit or one or more sensors configured to detect and/or measure one ormore aircraft quantities such as an aircraft angle and an aircraft anglerate. The system includes one or more flight controllers, which mayinclude an outer loop controller configured to control one or moreaircraft angles by receiving at least an input datum from one or moresensors and at least an aircraft angle from the inertial measurementunit, and in turn generate a rate setpoint, the rate setpointidentifying a desired rate of change of one or more aircraft quantitieslike aircraft angle, as a function of at least an input datum. Thesystem includes an inner loop controller configured to receive anaircraft angle rate, receive the rate setpoint from the outer loopcontroller, and generate a moment datum describing one or moremoments/forces required to be applied to the aircraft in order toachieve the one or more commanded angles and rates, as a function of therate setpoint. The system includes a mixer, the mixer configured toreceive the moment datum, perform a torque allocation as a function ofthe moment datum, and generate a motor torque command datum as afunction of the torque allocation.

In the following description, for the purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of the present invention. It will be apparent, however,that the present invention may be practiced without these specificdetails. As used herein, the word “exemplary” or “illustrative” means“serving as an example, instance, or illustration.” Any implementationdescribed herein as “exemplary” or “illustrative” is not necessarily tobe construed as preferred or advantageous over other implementations.All of the implementations described below are exemplary implementationsprovided to enable persons skilled in the art to make or use theembodiments of the disclosure and are not intended to limit the scope ofthe disclosure, which is defined by the claims. For purposes ofdescription herein, the terms “upper”, “lower”, “left”, “rear”, “right”,“front”, “vertical”, “horizontal”, and derivatives thereof shall relateto embodiments oriented as shown for exemplary purposes in FIG. 6 .Furthermore, there is no intention to be bound by any expressed orimplied theory presented in the preceding technical field, background,brief summary or the following detailed description. It is also to beunderstood that the specific devices and processes illustrated in theattached drawings, and described in the following specification, aresimply embodiments of the inventive concepts defined in the appendedclaims. Hence, specific dimensions and other physical characteristicsrelating to the embodiments disclosed herein are not to be considered aslimiting, unless the claims expressly state otherwise.

Referring now to FIG. 1 , an exemplary embodiment of a flight controlsystem 100 configured for use in electric aircraft is illustrated.Flight control system 100 includes a flight controller 124. Anycomponent of flight control system 100 and/or flight controller 124 mayinclude any computing device as described in this disclosure, includingwithout limitation a microcontroller, microprocessor, digital signalprocessor (DSP) and/or system on a chip (SoC) as described in thisdisclosure. A computing device may include, be included in, and/orcommunicate with a mobile device such as a mobile telephone orsmartphone. Flight control system 100 may include a single computingdevice operating independently, or may include two or more computingdevice operating in concert, in parallel, sequentially or the like; twoor more computing devices may be included together in a single computingdevice or in two or more computing devices. Flight control system 100may interface or communicate with one or more additional devices asdescribed below in further detail via a network interface device.Network interface device may be utilized for connecting flight controlsystem 100 to one or more of a variety of networks, and one or moredevices. Examples of a network interface device include, but are notlimited to, a network interface card (e.g., a mobile network interfacecard, a LAN card), a modem, and any combination thereof. Examples of anetwork include, but are not limited to, a wide area network (e.g., theInternet, an enterprise network), a local area network (e.g., a networkassociated with an office, a building, a campus or other relativelysmall geographic space), a telephone network, a data network associatedwith a telephone/voice provider (e.g., a mobile communications providerdata and/or voice network), a direct connection between two computingdevices, and any combinations thereof. A network may employ a wiredand/or a wireless mode of communication. In general, any networktopology may be used. Information (e.g., data, software etc.) may becommunicated to and/or from a computer and/or a computing device. Flightcontrol system 100 may include but is not limited to, for example, acomputing device or cluster of computing devices in a first location anda second computing device or cluster of computing devices in a secondlocation. Flight control system 100 may include one or more computingdevices dedicated to data storage, security, distribution of traffic forload balancing, and the like. Flight control system 100 may distributeone or more computing tasks as described below across a plurality ofcomputing devices of computing device, which may operate in parallel, inseries, redundantly, or in any other manner used for distribution oftasks or memory between computing devices. Flight control system 100 maybe implemented using a “shared nothing” architecture in which data iscached at the worker, in an embodiment, this may enable scalability offlight control system 100 and/or computing device.

With continued reference to FIG. 1 , flight control system 100 and/orflight controller may be designed and/or configured to perform anymethod, method step, or sequence of method steps in any embodimentdescribed in this disclosure, in any order and with any degree ofrepetition. For instance, Flight control system 100 may be configured toperform a single step or sequence repeatedly until a desired orcommanded outcome is achieved; repetition of a step or a sequence ofsteps may be performed iteratively and/or recursively using outputs ofprevious repetitions as inputs to subsequent repetitions, aggregatinginputs and/or outputs of repetitions to produce an aggregate result,reduction or decrement of one or more variables such as globalvariables, and/or division of a larger processing task into a set ofiteratively addressed smaller processing tasks. Flight control system100 may perform any step or sequence of steps as described in thisdisclosure in parallel, such as simultaneously and/or substantiallysimultaneously performing a step two or more times using two or moreparallel threads, processor cores, or the like; division of tasksbetween parallel threads and/or processes may be performed according toany protocol suitable for division of tasks between iterations. Personsskilled in the art, upon reviewing the entirety of this disclosure, willbe aware of various ways in which steps, sequences of steps, processingtasks, and/or data may be subdivided, shared, or otherwise dealt withusing iteration, recursion, and/or parallel processing.

With continued reference to FIG. 1 flight control system 100 and/orflight controller may be controlled by one or moreProportional-Integral-Derivative (PID) algorithms driven, for instanceand without limitation by stick, rudder and/or thrust control lever withanalog to digital conversion for fly by wire as described herein andrelated applications incorporated herein by reference. A “PIDcontroller”, for the purposes of this disclosure, is a control loopmechanism employing feedback that calculates an error value as thedifference between a desired setpoint and a measured process variableand applies a correction based on proportional, integral, and derivativeterms; integral and derivative terms may be generated, respectively,using analog integrators and differentiators constructed withoperational amplifiers and/or digital integrators and differentiators,as a non-limiting example. A similar philosophy to attachment of flightcontrol systems to sticks or other manual controls via pushrods and wiremay be employed except the conventional surface servos, steppers, orother electromechanical actuator components may be connected to thecockpit inceptors via electrical wires. Fly-by-wire systems may bebeneficial when considering the physical size of the aircraft, utilityof for fly by wire for quad lift control and may be used for remote andautonomous use, consistent with the entirety of this disclosure. Flightcontrol system 100 may harmonize vehicle flight dynamics with besthandling qualities utilizing the minimum amount of complexity whether itbe additional modes, augmentation, or external sensors as describedherein.

With continued reference to FIG. 1 , flight control system 100 includesat least a sensor 104. At least a sensor 104 may be mechanically andcommunicatively connected to one or more throttles. The throttle may beany throttle as described herein, and in non-limiting examples, mayinclude pedals, sticks, levers, buttons, dials, touch screens, one ormore computing devices, and the like. Additionally, a right-handfloor-mounted lift lever may be used to control the amount of thrustprovided by the lift fans or other propulsors. The rotation of a thumbwheel pusher throttle may be mounted on the end of this lever and maycontrol the amount of torque provided by the pusher motor, or one ormore other propulsors, alone or in combination. Any throttle asdescribed herein may be consistent with any throttle described in U.S.patent application Ser. No. 16/929,206 filed on Jul. 15, 2020 andtitled, “Hover and Thrust Control Assembly for Dual-Mode Aircraft”,which is incorporated herein in its entirety by reference. At least asensor 104 may be mechanically and communicatively connected to aninceptor stick. The pilot input may include a left-hand strain-gaugestyle STICK for the control of roll, pitch and yaw in both forward andassisted lift flight. A 4-way hat switch on top of the left-hand stickenables the pilot to set roll and pitch trim. Any inceptor stickdescribed herein may be consistent with any inceptor or directionalcontrol as described in U.S. patent application Ser. No. 17/001,845filed on Aug. 25, 2020 and titled, “A Hover and Thrust Control Assemblyfor a Dual-Mode Aircraft”, which is incorporated herein in its entiretyby reference.

Referring still to FIG. 1 , at least a sensor 104 may be mechanicallyand communicatively connected to a foot pedal. Flight control system 104may incorporate wheeled landing gear steerable by differential brakingaccessed by floor mounted pedals; in the event of installing such a footactuated “caveman” infrastructure, yaw control also may be affectedthrough differential foot pressure. A stick may be calibrated at zeroinput (relaxed state) and at the stops in pitch and roll. Thecalibration may be done in both directions of roll and both directionsof pitch. Any asymmetries may be handled by a bilinear calibration withthe breakpoint at the neutral point. Likewise, a yaw zero point maycorrespond to a relaxed state of an inceptor stick. The full-scaletorque in each twist direction may be independently calibrated to themaximum torque seen in the calibration process in that direction. In allphases of flight, the control surface deflections may be linearly mappedto their corresponding maximum stick deflections and neutral position.In the case of roll, where there may be more aileron deflection in thetrailing edge up direction, the degrees of deflection per pilot inputunit may be different in each direction, such that full surfacedeflection may be not reached until full stick deflection. When the liftfans are engaged, the pilot's stick inputs may correspond to roll andpitch attitude (+/−30 deg) and yaw rate (+/−60 deg/second) commands,which are also linearly mapped to the full range of stick travel. Abreakout force of 2-3 Newtons (0.5 lbf minimums mil spec 1797 minbreakout force) measured at center of stick grip position may be appliedprior to the linear mapping. Breakout force prevents adverse roll yawcoupling. In order to remove the need for constant control input insteady forward flight, pitch and roll trim may be available. Pitch trimmay be limited to +7 deg pitch up trim and −5 deg pitch down trim, whichmay be sufficient to trim for level flight over the entire center ofgravity and cruise airspeed range in non-limiting examples. Roll trimlimited to 2 degrees (average between the ailerons) may be alsoavailable. The trim may be applied after the breakout force to changethe input that center stick corresponds to. This trimmed command appliesto both the attitude commands when the lift rotors are powered, and thecontrol surface deflections at all times. In order to ensure the pilotcan always access the full capability of the aircraft, the mapping belowfrom pre-trim input to post-trim input may be used when trim is nonzero.Note that with positive trim, the effective sensitivity in the positivedirection has decreased while the sensitivity in the negative directionhas increased. This is a necessary byproduct of enforcing the constraintthat full stick deflection yields full control surface deflection. Thelift lever has very low additional breakout torque and requires aconstant (but adjustable) torque of 3.1 Nm during movement, whichtranslates to 2 lbf at the intended grip position. Control of the liftmotors may be only active when the assisted lift lever may be raisedabove 3.75 degrees from the full down stop (out of 25 degrees total).This may represent a debounce mechanism that may be determined based onthe friction of the assisted lift lever, the mass and the expectedcockpit vibration levels. A mechanical detent may be installed on thelift lever at an angle corresponding to 15% average torque in order toprovide kinesthetic feedback to the pilot of the minimum lift leversetting which provides adequate control authority via the lift fans.

With continued reference to FIG. 1 , flight control system 100 mayinclude at least a sensor 104 which may further include a sensor suite.One or more sensors may be communicatively connected to at least a pilotcontrol, the manipulation of which, may constitute at least an aircraftcommand. “Communicative connecting”, for the purposes of thisdisclosure, refers to two or more components electrically, or otherwiseconnected and configured to transmit and receive signals from oneanother. Signals may include electrical, electromagnetic, visual, audio,radio waves, or another undisclosed signal type alone or in combination.Any datum or signal herein may include an electrical signal. Electricalsignals may include analog signals, digital signals, periodic oraperiodic signal, step signals, unit impulse signal, unit ramp signal,unit parabolic signal, signum function, exponential signal, rectangularsignal, triangular signal, sinusoidal signal, sinc function, or pulsewidth modulated signal. At least a sensor 104 may include circuitry,computing devices, electronic components or a combination thereof thattranslates input datum 108 into at least an electronic signal configuredto be transmitted to another electronic component. At least a sensorcommunicatively connected to at least a pilot control may include asensor disposed on, near, around or within at least pilot control. Atleast a sensor may include a motion sensor. “Motion sensor”, for thepurposes of this disclosure refers to a device or component configuredto detect physical movement of an object or grouping of objects. One ofordinary skill in the art would appreciate, after reviewing the entiretyof this disclosure, that motion may include a plurality of typesincluding but not limited to: spinning, rotating, oscillating, gyrating,jumping, sliding, reciprocating, or the like. At least a sensor mayinclude, torque sensor, gyroscope, accelerometer, torque sensor,magnetometer, inertial measurement unit (IMU), pressure sensor, forcesensor, proximity sensor, displacement sensor, vibration sensor, amongothers. At least a sensor 104 may include a sensor suite which mayinclude a plurality of sensors that may detect similar or uniquephenomena. For example, in a non-limiting embodiment, sensor suite mayinclude a plurality of accelerometers, a mixture of accelerometers andgyroscopes, or a mixture of an accelerometer, gyroscope, and torquesensor.

Still referring to FIG. 1 , at least a sensor may include a plurality ofsensors in the form of individual sensors or a sensor suite working intandem or individually. A sensor suite may include a plurality ofindependent sensors, as described herein, where any number of thedescribed sensors may be used to detect any number of physical orelectrical quantities associated with an aircraft power system or anelectrical energy storage system. Independent sensors may includeseparate sensors measuring physical or electrical quantities that may bepowered by and/or in communication with circuits independently, whereeach may signal sensor output to a control circuit such as a usergraphical interface. In an embodiment, use of a plurality of independentsensors may result in redundancy configured to employ more than onesensor that measures the same phenomenon, those sensors being of thesame type, a combination of, or another type of sensor not disclosed, sothat in the event one sensor fails, the ability to detect phenomenon ismaintained and in a non-limiting example, a user alter aircraft usagepursuant to sensor readings. At least a sensor may be configured todetect pilot input from at least pilot control. At least pilot controlmay include a throttle lever, inceptor stick, collective pitch control,steering wheel, brake pedals, pedal controls, toggles, joystick. One ofordinary skill in the art, upon reading the entirety of this disclosurewould appreciate the variety of pilot input controls that may be presentin an electric aircraft consistent with the present disclosure. Inceptorstick may be consistent with disclosure of inceptor stick in U.S. patentapplication Ser. No. 17/001,845 and titled “A HOVER AND THRUST CONTROLASSEMBLY FOR DUAL-MODE AIRCRAFT”, which is incorporated herein byreference in its entirety. Collective pitch control may be consistentwith disclosure of collective pitch control in U.S. patent applicationSer. No. 16/929,206 and titled “HOVER AND THRUST CONTROL ASSEMBLY FORDUAL-MODE AIRCRAFT”, which is incorporated herein by reference in itsentirety.

Further referring to FIG. 1 , at least pilot control may be physicallylocated in the cockpit of the aircraft or remotely located outside ofthe aircraft in another location communicatively connected to at least aportion of the aircraft. “Communicatively connection”, for the purposesof this disclosure, is a process whereby one device, component, orcircuit is able to receive data from and/or transmit data to anotherdevice, component, or circuit; communicative connecting may be performedby wired or wireless electronic communication, either directly or by wayof one or more intervening devices or components. In an embodiment,communicative connecting includes electrically coupling an output of onedevice, component, or circuit to an input of another device, component,or circuit. Communicative connecting may be performed via a bus or otherfacility for intercommunication between elements of a computing device.Communicative connecting may include indirect connections via “wireless”connection, low power wide area network, radio communication, opticalcommunication, magnetic, capacitive, or optical coupling, or the like.At least pilot control may include buttons, switches, or other binaryinputs in addition to, or alternatively than digital controls aboutwhich a plurality of inputs may be received. At least pilot control maybe configured to receive pilot input. Pilot input may include a physicalmanipulation of a control like a pilot using a hand and arm to push orpull a lever, or a pilot using a finger to manipulate a switch. Pilotinput may include a voice command by a pilot to a microphone andcomputing system consistent with the entirety of this disclosure. One ofordinary skill in the art, after reviewing the entirety of thisdisclosure, would appreciate that this is a non-exhaustive list ofcomponents and interactions thereof that may include, represent, orconstitute, or be connected to at least a sensor 104.

In an embodiment, and still referring to FIG. 1 , at least a sensor 104may be attached to one or more pilot inputs and attached to one or morepilot inputs, one or more portions of an aircraft, and/or one or morestructural components, which may include any portion of an aircraft asdescribed in this disclosure. As used herein, a person of ordinary skillin the art would understand “attached” to mean that at least a portionof a device, component, or circuit is connected to at least a portion ofthe aircraft via a mechanical connection. Said mechanical connection caninclude, for example, rigid coupling, such as beam coupling, bellowscoupling, bushed pin coupling, constant velocity, split-muff coupling,diaphragm coupling, disc coupling, donut coupling, elastic coupling,flexible coupling, fluid coupling, gear coupling, grid coupling, hirthjoints, hydrodynamic coupling, jaw coupling, magnetic coupling, Oldhamcoupling, sleeve coupling, tapered shaft lock, twin spring coupling, ragjoint coupling, universal joints, or any combination thereof. In anembodiment, mechanical coupling can be used to connect the ends ofadjacent parts and/or objects of an electric aircraft. Further, in anembodiment, mechanical coupling can be used to join two pieces ofrotating electric aircraft components. Control surfaces may each includeany portion of an aircraft that can be moved or adjusted to affectaltitude, airspeed velocity, groundspeed velocity or direction duringflight. For example, control surfaces may include a component used toaffect the aircrafts' roll and pitch which may comprise one or moreailerons, defined herein as hinged surfaces which form part of thetrailing edge of each wing in a fixed wing aircraft, and which may bemoved via mechanical means such as without limitation servomotors,mechanical linkages, or the like, to name a few. As a further example,control surfaces may include a rudder, which may include, withoutlimitation, a segmented rudder. The rudder may function, withoutlimitation, to control yaw of an aircraft. Also, control surfaces mayinclude other flight control surfaces such as propulsors, rotatingflight controls, or any other structural features which can adjust themovement of the aircraft. A “control surface” as described herein, isany form of a mechanical linkage with a surface area that interacts withforces to move an aircraft. A control surface may include, as anon-limiting example, ailerons, flaps, leading edge flaps, rudders,elevators, spoilers, slats, blades, stabilizers, stabilators, airfoils,a combination thereof, or any other mechanical surface are used tocontrol an aircraft in a fluid medium. Persons skilled in the art, uponreviewing the entirety of this disclosure, will be aware of variousmechanical linkages that may be used as a control surface, as used anddescribed in this disclosure.

With continued reference to FIG. 1 , at least a sensor 104 is configuredto capture at least an input datum 108 from a pilot, remote user, or oneor more of the previous, alone or in combination. At least an inputdatum 108 may include a manipulation of one or more pilot input controlsas described above that correspond to a desire to affect an aircraft'strajectory as a function of the movement of one or more flightcomponents and one or more propulsors, alone or in combination. “Flightcomponents”, for the purposes of this disclosure, includes componentsrelated to, and mechanically connected to an aircraft that manipulates afluid medium in order to propel and maneuver the aircraft through thefluid medium. The operation of the aircraft through the fluid mediumwill be discussed at greater length hereinbelow. At least an input datum108 may include information gathered by one or more sensors.

With continued reference to FIG. 1 , a “datum”, for the purposes of thisdisclosure, refers to at least an element of data identifying and/or apilot input or command. At least pilot control may be communicativelyconnected to any other component presented in system, the communicativeconnection may include redundant connections configured to safeguardagainst single-point failure. Pilot input may indicate a pilot's desireto change the heading or trim of an electric aircraft. Pilot input mayindicate a pilot's desire to change an aircraft's pitch, roll, yaw, orthrottle. Aircraft trajectory is manipulated by one or more controlsurfaces and propulsors working alone or in tandem consistent with theentirety of this disclosure, hereinbelow. Pitch, roll, and yaw may beused to describe an aircraft's attitude and/or heading, as theycorrespond to three separate and distinct axes about which the aircraftmay rotate with an applied moment, torque, and/or other force applied toat least a portion of an aircraft. “Pitch”, for the purposes of thisdisclosure refers to an aircraft's angle of attack, that is thedifference between the aircraft's nose and the horizontal flighttrajectory. For example, an aircraft pitches “up” when its nose isangled upward compared to horizontal flight, like in a climb maneuver.In another example, the aircraft pitches “down”, when its nose is angleddownward compared to horizontal flight, like in a dive maneuver. Whenangle of attack is not an acceptable input to any system disclosedherein, proxies may be used such as pilot controls, remote controls, orsensor levels, such as true airspeed sensors, pitot tubes,pneumatic/hydraulic sensors, and the like. “Roll” for the purposes ofthis disclosure, refers to an aircraft's position about its longitudinalaxis, that is to say that when an aircraft rotates about its axis fromits tail to its nose, and one side rolls upward, like in a bankingmaneuver. “Yaw”, for the purposes of this disclosure, refers to anaircraft's turn angle, when an aircraft rotates about an imaginaryvertical axis intersecting the center of the earth and the fuselage ofthe aircraft. “Throttle”, for the purposes of this disclosure, refers toan aircraft outputting an amount of thrust from a propulsor. Pilotinput, when referring to throttle, may refer to a pilot's desire toincrease or decrease thrust produced by at least a propulsor.

With continued reference to FIG. 1 , at least an input datum 104 mayinclude an electrical signal. At least an input datum 104 may includemechanical movement of any throttle consistent with the entirety of thisdisclosure. Electrical signals may include analog signals, digitalsignals, periodic or aperiodic signal, step signals, unit impulsesignal, unit ramp signal, unit parabolic signal, signum function,exponential signal, rectangular signal, triangular signal, sinusoidalsignal, sinc function, or pulse width modulated signal. At least asensor may include circuitry, computing devices, electronic componentsor a combination thereof that translates pilot input into at least aninput datum 104 configured to be transmitted to any other electroniccomponent.

With continued reference to FIG. 1 , flight control system 100 includesan inertial measurement unit (IMU) 112. IMU 112 may be an IMU asdescribed herein. IMU 112 is configured to detect at least an aircraftangle 116. At least an aircraft angle 116 may include any informationabout the orientation of the aircraft in three-dimensional space such aspitch angle, roll angle, yaw angle, or some combination thereof. Innon-limiting examples, at least an aircraft angle may use one or morenotations or angular measurement systems like polar coordinates,cartesian coordinates, cylindrical coordinates, spherical coordinates,homogenous coordinates, relativistic coordinates, or a combinationthereof, among others. IMU 112 is configured to detect at least anaircraft angle rate 116. At least an aircraft angle rate 116 may includeany information about the rate of change of any angle associated with anelectrical aircraft as described herein. Any measurement system may beused in the description of at least an aircraft angle rate 116.

With continued reference to FIG. 1 , flight control system 100 includesflight controller 124. Flight controller 124 may be responsible only formapping the pilot inputs such as input datum 108, attitude such as atleast an aircraft angle 116, and body angular rate measurement such asat least an aircraft angle rate 120 to motor torque levels necessary tomeet the input datum 108. In a non-limiting exemplary embodiment, flightcontroller 124 may include the nominal attitude command (ACAH)configuration, the flight controller 124 may make the vehicle attitudetrack the pilot attitude while also applying the pilot-commanded amountof assisted lift and pusher torque which may be encapsulated withinmotor torque command 148. The flight controller is responsible only formapping the pilot inputs, attitude, and body angular rate measurementsto motor torque levels necessary to meet the input datum 108. In thenominal attitude command (ACAH) configuration, flight controller 124makes the vehicle attitude track the pilot attitude while also applyingthe pilot commanded amount of assisted lift and pusher torque. Flightcontroller 124 may include the calculation and control of avionicsdisplay of critical envelope information i.e., stall warning, vortexring state, pitch limit indicator, angle of attack, transitionenvelopes, etc. Flight controller 124 may calculate, command, andcontrol trim assist, turn coordination, pitch to certain gravitationalforces, automation integration: attitude, position hold, LNAV, VNAVetc., minimum hover thrust protection, angle of attack limits, etc.,precision Autoland, other aspects of autopilot operations, advancedperception of obstacles for ‘see and avoid’ missions, and remoteoperations, among others. Flight control system 100 includes flightcontroller 124, wherein the flight controller 124 may further include aprocessor. The processor may include one or more processors as describedherein, in a near limitless arrangement of components.

With continued reference to FIG. 1 , flight control system 100 includesan outer loop controller 128. Outer loop controller 128 may include oneor more computing devices consistent with this disclosure and/or one ormore components and/or modules thereof. Outer loop controller 128 may beimplemented using a microcontroller, a hardware circuit such as an FPGA,system on a chip, and/or application specific integrated circuit (ASIC).Outer loop controller 128 may be implemented using one or more analogelements such as operational amplifier circuits, including operationalamplifier integrators and/or differentiators. Outer loop controller 128may be implemented using any combination of the herein describedelements or any other combination of elements suitable therefor. Outerloop controller 128 may be configured to input one or more parameters,such as input datum 108 and/or at least an aircraft angle 116 and outputrate setpoint 132. Outer loop controller 128 may periodically detect oneor more errors between aircraft angles and commanded angles in any oneof pitch, roll, yaw, or a combination thereof. For example, and withoutlimitation, outer loop controller 128 may detect the error between thecommanded and detected aircraft angle and command one or more propulsorsand or flight components consistent with the entirety of this disclosureto reduce said error in one or more iterations. Outer loop controller128 may be closed by a PI controller with integral anti-windup viaback-calculation. Additional logic is present to prevent integral windupwhile grounded on a not perfectly level surface. Gains may be reduced atlarge amplitude in order to reduce overshoot on large inputs. Thisexcessive overshoot may be due in part to linear systems having constantpercent overshoot, so at larger amplitudes, the absolute value of theovershoot becomes (potentially unacceptably) large. Additionally, onlarge step inputs, motor saturation (a nonlinear effect) may occur forextended periods of time and causes overshoot to increase. In extremecases, the occurrence of motor saturation without any gain reduction maylead to unrecoverable tumbles. This gain reduction may be implemented asa (soft) rate command limit. In particular, this reduction may be givenby the piecewise combination of a linear function and the square rootfunction. Note that the input/output relationship may be monotonicallyincreasing, so increased angle error or integral action always makes itthrough to the inner loop, even if the gain reduction may be engaged.For inputs less than the knee, set to 20 deg/s, the input may be notchanged. Above the knee, the output may be given bysign(input)*sqrt(abs(input)*knee). The effective gain at any point tothe right of the knee may be then given by sqrt(abs(input)*knee)/input.This gain decrease at large amplitudes has been shown in simulation tostabilize the vehicle when subject to inputs that would otherwisedestabilize the vehicle into an unrecoverable tumble. For the vastmajority of maneuvers, this soft rate limit may be set high enough tonot be noticeable.

With continued reference to FIG. 1 , outer loop controller 128 isconfigured to receive at least an input datum 108 from at least a sensor104. Input datum 108 represents the pilot's desire to change an electricaircraft's heading or power output. Input datum 108 may be transmittedto one or more components from the pilot control to which it may beconnected. Outer loop controller 128 may include circuitry, components,processors, transceivers, or a combination thereof configured to receiveand/or send electrical signals. Input datum 108 and other inputs to thissystem may include pilot manipulations of physical control interfaces,remote signals generated from electronic devices, voice commands,physiological readings like eye movements, pedal manipulation, or acombination thereof, to name a few. Outer loop controller 128 mayinclude a proportional-integral-derivative (PID) controller. PIDcontrollers may automatically apply accurate and responsive correctionto a control function in a loop, such that over time the correctionremains responsive to the previous output and actively controls anoutput. Flight controller 104 may include damping, including criticaldamping to attain the desired setpoint, which may be an output to apropulsor in a timely and accurate way.

With continued reference to FIG. 1 , outer loop controller 128 isconfigured to receive at least an aircraft angle 116 from the inertialmeasurement unit 112. Inertial measurement unit 112, as discussed, maybe configured to detect at least an aircraft angle 116. Outer loopcontroller 128 may include components, circuitry, receivers,transceivers, or a combination thereof configured to receive at least anaircraft angle 116 in the form of one or more electrical signalsconsistent with the description herein. Outer loop controller 128 isconfigured to generate rate setpoint 132 as a function of at least aninput datum 108. The flight controller uses an outer angle loop drivingan inner rate loop to provide closed loop control with setpoints ofdesired pitch attitude, roll attitude, and yaw rate provided directly bythe pilot. The outer (angle) loop provides a rate setpoint. Ratesetpoint 132 may include the desired rate of change of one or moreangles describing the aircraft's orientation, heading, and propulsion,or a combination thereof. Rate setpoint 132 may include the pilot'sdesired rate of change of aircraft pitch angle, consistent with pitchangles, and largely at least an aircraft angle 116 in the entirety ofthis disclosure. Rate setpoint 132 may include a measurement in aplurality of measurement systems including quaternions or any othermeasurement system as described herein.

With continued reference to FIG. 1 , flight controller 124 includesinner loop controller 136. Inner loop controller 136 may be implementedin any manner suitable for implementation of outer loop controller. Theinner loop of the flight controller may be composed of a lead-lag filterfor roll rate, pitch rate, and yaw rate, and an integrator that actsonly on yaw rate. Integrators may be avoided on the roll and pitch ratebecause they introduce additional phase lag that, coupled with the phaselag inherent to slow lift fans or another type of one or morepropulsors, limits performance. Furthermore, it may not be necessary tohave good steady state error in roll and pitch rate, which an integratorhelps achieve in yaw rate. A final component of the inner loop mayinclude gain scheduling on lift lever input. As previously discussed,the only controller change between low speed flight and fully wing-borneflight may be this gain scheduling. The plot below shows the input tooutput gain of this function for varying lift lever inputs. At anythingabove the assisted lift input corresponding to zero airspeed flight, thefull requested moment from the inner loop may be sent to the mixer. Atassisted lift levels lower than this, the requested moment from theinner loop may be multiplied by a gain that linearly decays to zero asshown in the plot below. The exact shape of this gain reduction may beopen to change slightly. Experimentation in simulation has shown thatanything between a square root function up to the IGE average torquesetting and the linear map shown above works acceptably. Because themoment that can be generated by the control surfaces in pitch may besuch a strong function of angle of attack, the relatively smalldifference in hover moment achieved between the linear and square rootmaps may be washed out by the angle of attack variation in a transition.At low lift lever input, the plane would have to have significantunpowered lift (and therefore airspeed) to not lose altitude. In thiscase, the control surface effectivity will be significant, and fullmoment production from the lift motors will not be necessary. When thelift lever may be all the way down, the lift motors may stop rotationand stow into a low drag orientation. Then, the only control authoritycomes from the aerodynamic control surfaces, and the plane controlledexclusively via manual pilot inputs. On transition out from vertical tocruise flight, the coordination and scheduling of control may beintuitive and straightforward. In a non-limiting example, during thetransition in, or decelerating from an aborted takeoff, it may beimportant that the pilot not decrease assisted lift below a 15% averagetorque threshold in order to maintain aircraft control and not developan unrecoverable sink rate when operating in certain airspeed regimessuch as the transition regime. A mechanical detent may be installed inthe lift lever, throttle, or any control input, to provideproprioceptive feedback when crossing this threshold which should occuroperationally only during the terminal phases of a vertical landing.

With continued reference to FIG. 1 , inner loop controller 136 isconfigured to receive at least an aircraft angle rate 120. Inner loopcontroller 136 is configured to receive the rate setpoint 132 from theouter loop controller 128. Inner loop controller 136 is configured togenerate a moment datum 140 as a function of the rate setpoint 132.Moment datum 140 may include any information describing the moment of anaircraft. Moment datum 140 includes information regarding pilot's desireto apply a certain moment or collection of moments on one or moreportions of an electric aircraft, including the entirety of theaircraft.

With continued reference to FIG. 1 , inner loop controller 136 mayinclude a lead-lag-filter. Inner loop controller 136 may include anintegrator. The attitude controller gains are scheduled such that fullgain authority may be only achieved when the assisted lift lever may begreater than 50% torque, which corresponds to a nominal torque requiredto support the aircraft without fully developed lift from the wing. Ataverage torque levels lower than said nominal levitation torque, theoutput of the inner loop (desired moment vector to apply to the vehicle)may be directly scaled down. This decrease in moment generated at thelift rotors may be designed to be directly complementary to the increasein aerodynamic control surface effectivity as the dynamic pressurebuilds on the flying wing and the flying surfaces. As a result, thetotal moment applied to the vehicle for a given pilot input may be keptnear constant.

With continued reference to FIG. 1 , flight control system 100 includesmixer 144. Mixer 144 may identify how much moment was generated byaerodynamic forces acting on one or more flight components andpropulsors and may feed this back to inner loop controller 136 and outerloop controller 128 to prevent integral windup. A dynamic inverse of thelift rotor system may be applied to the motor torque command 148 tocompensate for the rotor inertia, which will be discussed at greaterlength hereinbelow. The input datum 108, which represents one or moredesires of a pilot or user that may include pusher torques, may bedirectly passed through the controller; full rotation of the pusherthrottle yields full torque at the pusher. As discussed previously, thecontrol surface deflections are driven directly from the pilot roll,pitch, and yaw inputs, which may also be included in input datum 108.Mixer 144 may map desired vehicle level control torques (as produced bythe inner loop controller 136) to appropriate actuator outputs viaknowledge of the vehicle layout and properties. In the case that motorsaturation prevents the achievement of the desired vehicle level controltorques, the mixer will deprioritize the yaw moment, then assisted lift,then roll moment, and finally pitch moment.

With continued reference to FIG. 1 , mixer 144 may include a logiccircuit. Mixer 144 may be implemented using an electrical logic circuit.“Logic circuits”, for the purposes of this disclosure, refer to anarrangement of electronic components such as diodes or transistorsacting as electronic switches configured to act on one or more binaryinputs that produce a single binary output. Logic circuits may includedevices such as multiplexers, registers, arithmetic logic units (ALUs),computer memory, and microprocessors, among others. In modern practice,metal-oxide-semiconductor field-effect transistors (MOSFETs) may beimplemented as logic circuit components. Mixer 144 may be implementedusing a processor. Mixer 144 is configured to receive the moment datum140 for at least a propulsor from inner loop controller 136. Mixer 144solves at least an optimization problem. At least an optimizationproblem may include solving the pitch moment function that may be anonlinear program.

With continued reference to FIG. 1 , a “mixer”, for the purposes of thisdisclosure, may be a component that takes in at least an incomingsignal, such as moment datum 140 including plurality of attitudecommands and allocates one or more outgoing signals, such as modifiedattitude commands and output torque command, or the like, to at least apropulsor, flight component, or one or more computing devices connectedthereto. One of ordinary skill in the art, after reading the entirety ofthis disclosure, would be aware that a mixer, as used herein, mayadditionally or alternatively be described as performing “controlallocation” or “torque allocation”. For example, mixer may take incommands to alter aircraft trajectory that requires a change in pitchand yaw. Mixer may allocate torque to at least one propulsor (or more)that do not independently alter pitch and yaw in combination toaccomplish the command to change pitch and yaw. More than one propulsormay be required to adjust torques to accomplish the command to changepitch and yaw, mixer would take in the command and allocate thosetorques to the appropriate propulsors consistent with the entirety ofthis disclosure. One of ordinary skill in the art, after reading theentirety of this disclosure, will appreciate the limitless combinationof propulsors, flight components, control surfaces, or combinationsthereof that could be used in tandem to generate some amount ofauthority in pitch, roll, yaw, and lift of an electric aircraftconsistent with this disclosure. Mixer may be a nonlinear program-basedmixer that create new frequencies from two signals applied to it. Inmost applications, two signals are applied to mixer, and it produces newsignals at the sum and difference of the original frequencies. Otherfrequency component may also be produced in a practical frequency mixer.One of ordinary skill in the art would understand that, in general,mixers are widely used to shift signals from one frequency range toanother, a process known as heterodyning. Another form of mixer operatesby switching, with the smaller input signal being passed inverted ornoninverted according to the phase of the local oscillator (LO). Thiswould be typical of the normal operating mode of a packaged doublebalanced mixer, with the local oscillator drive considerably higher thanthe signal amplitude. Mixer may be consistent with any mixer describedherein. Mixer may be implemented using an electrical logic circuit.“Logic circuits”, for the purposes of this disclosure, refer to anarrangement of electronic components such as diodes or transistorsacting as electronic switches configured to act on one or more binaryinputs that produce a single binary output. Logic circuits may includedevices such as multiplexers, registers, arithmetic logic units (ALUs),computer memory, and microprocessors, among others. In modern practice,metal-oxide-semiconductor field-effect transistors (MOSFETs) may beimplemented as logic circuit components. Mixer may be implemented usinga processor. Mixer is configured to receive the initial vehicle torquesignal for at least a propulsor from flight controller. Mixer solves atleast an optimization problem. At least an optimization problem mayinclude solving the pitch moment function that may be a nonlinearprogram. Torque allocation performed by mixer 144 may be consistent withthe description of torque allocation in U.S. patent application Ser. No.17/197,427 filed on Mar. 10, 2021 and titled, “SYSTEM AND METHOD FORFLIGHT CONTROL IN ELECTRIC AIRCRAFT”, which is incorporated herein inits entirety by reference.

With continued reference to FIG. 1 , mixer may be configured to solve atleast an optimization problem, which may be an objective function. An“objective function,” as used in this disclosure, is a mathematicalfunction with a solution set including a plurality of data elements tobe compared. Mixer may compute a score, metric, ranking, or the like,associated with each performance prognoses and candidate transferapparatus and select objectives to minimize and/or maximize thescore/rank, depending on whether an optimal result may be represented,respectively, by a minimal and/or maximal score; an objective functionmay be used by mixer to score each possible pairing. At least anoptimization problem may be based on one or more objectives, asdescribed below. Mixer may pair a candidate transfer apparatus, with agiven combination of performance prognoses, that optimizes the objectivefunction. In various embodiments solving at least an optimizationproblem may be based on a combination of one or more factors. Eachfactor may be assigned a score based on predetermined variables. In someembodiments, the assigned scores may be weighted or unweighted. Solvingat least an optimization problem may include performing a greedyalgorithm process, where optimization may be performed by minimizingand/or maximizing an output of objective function. A “greedy algorithm”is defined as an algorithm that selects locally optimal choices, whichmay or may not generate a globally optimal solution. For instance, mixermay select objectives so that scores associated therewith are the bestscore for each goal. For instance, in non-limiting illustrative example,optimization may determine the pitch moment associated with an output ofat least a propulsor based on an input.

Still referring to FIG. 1 , at least an optimization problem may beformulated as a linear objective function, which mixer may optimizeusing a linear program such as without limitation a mixed-integerprogram. A “linear program,” as used in this disclosure, is a programthat optimizes a linear objective function, given at least a constraint;a linear program maybe referred to without limitation as a “linearoptimization” process and/or algorithm. For instance, in non-limitingillustrative examples, a given constraint might be torque limit, and alinear program may use a linear objective function to calculate maximumoutput based on the limit. In various embodiments, mixer may determine aset of instructions towards achieving a user's goal that maximizes atotal score subject to a constraint that there are other competingobjectives. A mathematical solver may be implemented to solve for theset of instructions that maximizes scores; mathematical solver may beimplemented on mixer and/or another device in flight control system 100,and/or may be implemented on third-party solver. At least anoptimization problem may be formulated as nonlinear least squaresoptimization process. A “nonlinear least squares optimization process,”for the purposes of this disclosure, is a form of least squares analysisused to fit a set of m observations with a model that is non-linear in nunknown parameters, where m is greater than or equal to n. The basis ofthe method is to approximate the model by a linear one and to refine theparameters by successive iterations. A nonlinear least squaresoptimization process may output a fit of signals to at least apropulsor. Solving at least an optimization problem may includeminimizing a loss function, where a “loss function” is an expression anoutput of which a ranking process minimizes to generate an optimalresult. As a non-limiting example, mixer may assign variables relatingto a set of parameters, which may correspond to score components asdescribed above, calculate an output of mathematical expression usingthe variables, and select an objective that produces an output havingthe lowest size, according to a given definition of “size,” of the setof outputs representing each of plurality of candidate ingredientcombinations; size may, for instance, included absolute value, numericalsize, or the like. Selection of different loss functions may result inidentification of different potential pairings as generating minimaloutputs.

With continued reference to FIG. 1 , mixer may include an inertiacompensator. An inertia compensator as described herein may beimplemented in any one or more separate subsystems separate from anymixer as described herein and operate similarly to any inertiacompensator implemented in a mixer. An inertia compensator may includeone or more computing devices, an electrical component, circuitry, oneor more logic circuits or processors, or the like, which may configuredto compensate for inertia in one or more propulsors present in system.Mixer may be configured, in general, to output signals and commandpropulsors to produce a certain amount of torque; however, real-worldpropulsors contain mass, and therefore have inertia. “Inertia”, for thepurposes of this disclosure, is a property of matter by which itcontinues in its existing state of rest or uniform motion in a straightline, unless that state may be changed by an external force.Specifically, in this case, a massive object requires more force ortorque to start motion than may be required to continue producingtorque. In a control system, mixer must therefore modulate the would-besignal to account for inertia of the physical system being commanded.The inertia compensator may make appropriate calculations based onmodified attitude command, output torque command, and otherconsiderations like environmental conditions, available power, vehicletorque limits, among others. Inertia compensator may adjust vehicletorque limits for certain periods of time wherein, for example, outputtorque command may be allowed to overspeed a propulsor to start thepropulsor's rotating physical components and then quickly step down thetorque as required to maintain the commanded torque. The inertiacompensator which may include a lead filter.

Mixer 144 is configured to generate motor torque command 148 as afunction of the torque allocation. Motor torque command 148 may includeat least a torque vector. Motor torque command 148 may be represented inany suitable form, which may include, without limitation, vectors,matrices, coefficients, scores, ranks, or other numerical comparators,and the like. A “vector” as defined in this disclosure is a datastructure that represents one or more quantitative values and/ormeasures of forces, torques, signals, commands, or any other datastructure as described in the entirety of this disclosure. A vector maybe represented as an n-tuple of values, where n is at least two values,as described in further detail below; a vector may alternatively oradditionally be represented as an element of a vector space, defined asa set of mathematical objects that can be added together under anoperation of addition following properties of associativity,commutativity, existence of an identity element, and existence of aninverse element for each vector, and can be multiplied by scalar valuesunder an operation of scalar multiplication compatible with fieldmultiplication, and that has an identity element is distributive withrespect to vector addition, and may be distributive with respect tofield addition. Each value of n-tuple of values may represent ameasurement or other quantitative value associated with a given categoryof data, or attribute, examples of which are provided in further detailbelow; a vector may be represented, without limitation, in n-dimensionalspace using an axis per category of value represented in n-tuple ofvalues, such that a vector has a geometric direction characterizing therelative quantities of attributes in the n-tuple as compared to eachother. Two vectors may be considered equivalent where their directions,and/or the relative quantities of values within each vector as comparedto each other, are the same; thus, as a non-limiting example, a vectorrepresented as [5, 10, 15] may be treated as equivalent, for purposes ofthis disclosure, as a vector represented as [1, 2, 3]. Vectors may bemore similar where their directions are more similar, and more differentwhere their directions are more divergent; however, vector similaritymay alternatively or additionally be determined using averages ofsimilarities between like attributes, or any other measure of similaritysuitable for any n-tuple of values, or aggregation of numericalsimilarity measures for the purposes of loss functions as described infurther detail below. Any vectors as described herein may be scaled,such that each vector represents each attribute along an equivalentscale of values. Each vector may be “normalized,” or divided by a“length” attribute, such as a length attribute l as derived using aPythagorean norm:

${l = \sqrt{\sum\limits_{i = 0}^{n}a_{i}^{2}}},$where a_(i) is attribute number i of the vector. Scaling and/ornormalization may function to make vector comparison independent ofabsolute quantities of attributes, while preserving any dependency onsimilarity of attributes. One of ordinary skill in the art wouldappreciate a vector to be a mathematical value consisting of a directionand magnitude.

With continued reference to FIG. 1 , “torque”, for the purposes of thisdisclosure, refers to a twisting force that tends to cause rotation.Torque is the rotational equivalent of linear force. In threedimensions, the torque may be a pseudovector; for point particles, itmay be given by the cross product of the position vector (distancevector) and the force vector. The magnitude of torque of a rigid bodydepends on three quantities: the force applied, the lever arm vectorconnecting the point about which the torque may be being measured to thepoint of force application, and the angle between the force and leverarm vectors. A force applied perpendicularly to a lever multiplied byits distance from the lever's fulcrum (the length of the lever arm) maybe its torque. A force of three newtons applied two meters from thefulcrum, for example, exerts the same torque as a force of one newtonapplied six meters from the fulcrum. The direction of the torque can bedetermined by using the right-hand grip rule: if the fingers of theright hand are curled from the direction of the lever arm to thedirection of the force, then the thumb points in the direction of thetorque. One of ordinary skill in the art would appreciate that torquemay be represented as a vector, consistent with this disclosure, andtherefore includes a magnitude of force and a direction. “Torque” and“moment” are equivalents for the purposes of this disclosure. Any torquecommand or signal herein may include at least the steady state torque toachieve the initial vehicle torque signal 108 output to at least apropulsor.

With continued reference to FIG. 1 , as previously disclosed, solving atleast an optimization problem may include solving sequential problemsrelating to vehicle-level inputs to at least a propulsor, namely pitch,roll, yaw, and collective force. Mixer 144 may solve at least anoptimization problem in a specific order. An exemplary sequence ispresented here in FIG. 1 . According to exemplary embodiments, mixer 144may solve at least an optimization problem wherein at least anoptimization problem includes a pitch moment function. Solving may beperformed using a nonlinear program and/or a linear program. Mixer maysolve at least an optimization problem wherein solving at least anoptimization program may include solving a roll moment functionutilizing a nonlinear program to yield the desired amount of roll momentas a function of the desired amount of pitch moment. Mixer 144 may solveat least an optimization problem wherein solving at least anoptimization program may include solving a collective force functionutilizing a nonlinear program to yield the desired amount of collectiveforce as a function of the desired amount of pitch moment and thedesired amount of roll moment. Mixer 144 may solve at least anoptimization problem wherein solving at least an optimization programmay include solving a yaw moment function utilizing a nonlinear programto yield the desired amount of yaw moment, as a function of the desiredamount of pitch moment, the desired amount of roll moment, and thedesired amount of collective force. One of ordinary skill in the art,after reading the entirety of this disclosure, will appreciate that anyforce program may be implemented as a linear or non-linear program, asany linear program may be expressed as a nonlinear program.

With continued reference to FIG. 1 , mixer 144 may include one or morecomputing devices as described herein. Mixer 144 may be a separatecomponent or grouping of components from those described herein. Mixer144 is configured to generate motor torque command 148 as a function ofthe torque allocation. Mixer 144 may be configured to allocate a portionof total possible torque amongst one or more propulsors based onrelative priority of a plurality attitude control commands and desiredaircraft maneuver. In a non-limiting illustrative example, torqueallocation between two attitude control components (e.g., pitch and rollor roll and yaw) may be based on the relative priorities of those twoattitude control components. Priority refers to how important to thesafety of the aircraft and any users while performing the attitudecontrol component may be relative to the other attitude controlcommands. Priority may also refer to the relative importance of eachattitude control component to accomplish one or more desired aircraftmaneuvers. For example, pitch attitude control component may be thehighest priority, followed by roll, lift, and yaw attitude controlcomponents. In another example, the relative priority of the attitudecomponents may be specific to an environment, aircraft maneuver, missiontype, aircraft configuration, or other factors, to name a few. Torqueallocator may set the highest priority attitude control component torqueallocation as close as possible given the torque limits as described inthis disclosure to the original command for the higher-priority attitudecontrol component, in the illustrative example, pitch, then project tothe value possible for the lower priority attitude control component, inthis case, lift. The higher priority attitude control component in thefirst torque allocation may be the attitude control component with thehighest overall priority. This process may be then repeated with lowerpriority attitude control component from the above comparison and thenext highest down the priority list. In a non-limiting illustrativeexample, the next two-dimensional torque allocation problem solved wouldinclude lift and roll attitude control commands. In embodiments, thelower priority attitude command component has already been set form theprevious two-dimensional torque allocation, so this may be projectingthe closest possible value for the third-level attitude command (roll inthis example). This process would repeat again for the third and fourthattitude components, in this non-limiting example, roll and yaw attitudecontrol components. Since roll may be prioritized over yaw, the rollattitude control command would be preserved, and yaw would be sacrificedas a function of the vehicle torque limits as described herein. Afterthe sequence of two-dimensional attitude control component torqueallocation are completed and four prioritized attitude componentcommands are set, one or more components may send out commands to flightcontrol surfaces/propulsors to generate the set torque values allocatedin the foregoing process. As a non-limiting example of one step in thetorque allocation process, pitch axis may represent the command orplurality of attitude commands inputted to mixer 144 as describedherein, such as moment datum 140. Pitch axis may be conditioned oraltered to be inputted to mixer 144. For example, and withoutlimitation, initial vehicle torque signal may include pitch and liftcommands within plurality of attitude commands. Mixer 144 may alsoreceive at least a moment datum 140, which may be represented withoutlimitation by a box plotted within the pitch and lift axes. A pointwhere pitch command and lift command intersect may represent initialvehicle torque signal as projected onto exemplary graph of pitch andlift axes, which may be the same or similar to initial vehicle torquesignal as disclosed in the entirety of this disclosure. Mixer 144utilizes prioritization data as described in the entirety of thisdisclosure to solve this two-dimensional problem by preserving thehigher priority command and sacrificing the lower priority command. Thisprioritization preservation process may be illustrated, as anon-limiting example by placement of a modified attitude command,wherein the pitch command was preserved (horizontally translated andtherefore unchanged from the initial command), while the lift commandwas lessened to bring the modified attitude command within vehicletorque limits (the box). The modified attitude command, as discussed inthe entirety of this disclosure, may be further combined, modified,conditioned, or otherwise adjusted to produce output torque command tothe plurality of propulsors. The remaining vehicle torque represents theremaining torque capability in one or more propulsors before, during,and after an aircraft maneuver. The remaining vehicle torque may includean individual propulsor's remaining torque capability, one or more ofpitch, roll, yaw, and lift, capabilities of one or more propulsors, theremaining vehicle-level torque or power for subsequent maneuvers. Theremaining vehicle torque may be displayed to a pilot or user. Theabove-described may be a non-limiting example of one step in the torqueallocation process. Torque allocation process may be similar or the sameprocess as described above with the torque limits adjusted for inertiacompensation. Mixer 144 may be disposed fully or partially within mixerany mixer as disclosed herein. Mixer 144 may include one or morecomputing devices as described herein. Mixer 144 also receives at leasta vehicle torque limit represented by an imaginary box plotted withinthe pitch and lift axes, which may be the same as, or similar to atleast a vehicle torque limit. Here instead of the box being made ofstraight linear sides, the inertia compensation as previously discussedcreates curved limits, wherein certain plurality of attitude commandsmay be allowed whereas without inertia compensation they would beoutside of the limits. Where the pitch command and lift commandintersect may be the initial vehicle torque signal, which may be thesame or similar to initial vehicle torque signal as disclosed in theentirety of this disclosure. Mixer 144 utilizes prioritization data asdescribed in the entirety of this disclosure to solve thistwo-dimensional problem by preserving the higher priority command andsacrificing the lower priority command. This prioritization preservationprocess may be shown by the placement of modified attitude command,wherein the pitch command was preserved (horizontally translated andtherefore unchanged from the initial command), while the lift commandwas lessened to bring the modified attitude command within vehicletorque limits (the box). Motor torque command 148 effectively commandsthe amount of torque to one or more propulsors to accomplish the closestvehicle level torque to initial vehicle torque signal as possible givencertain limits, maneuvers, and aircraft conditions. Modified attitudecommand, as discussed in the entirety of this disclosure, may be furthercombined, modified, conditioned, or otherwise adjusted to produce outputtorque command to the plurality of propulsors. The remaining vehicletorque represents the remaining torque capability in one or morepropulsors before, during, and after an aircraft maneuver. The remainingvehicle torque may include an individual propulsor's remaining torquecapability, one or more of pitch, roll, yaw, and lift, capabilities ofone or more propulsors, the remaining vehicle-level torque or power forsubsequent maneuvers. Remaining vehicle torque may be displayed to apilot or user.

With continued reference to FIG. 1 , motor torque command 148 may betransmitted to a plurality of flight components. Flight components andcontrol surfaces may be commanded exclusively by the pilot or by one ormore users, or one or more computing devices. Flight components may beconsistent with any of the flight components and/or control surfaces asdescribed herein. “Flight components”, for the purposes of thisdisclosure, includes components related to, and mechanically connectedto an aircraft that manipulates a fluid medium in order to propel andmaneuver the aircraft through the fluid medium. The operation of theaircraft through the fluid medium will be discussed at greater lengthhereinbelow. At least an input datum 104 may include informationgathered by one or more sensors. In non-limiting embodiments, flightcomponents may include propulsors, wings, rotors, propellers, pusherpropellers, ailerons, elevators, stabilizers, stabilators, and the like,among others.

Referring now to FIG. 2 , an exemplary embodiment of outer loopcontroller 200 is presented in block diagram form. Outer loop controller200 may be consistent with any outer loop controller as describedherein. Outer loop controller 200 may include attitude error 204.Attitude error 204 may include a measurement of the difference betweenthe commanded at least an aircraft angle 116 and the actual angle of theaircraft in any of pitch, roll, yaw, or a combination thereof. Theattitude error 204 may include a percentage, measurement in degrees,measurement in radians, or one or more representations of a differencein commanded aircraft angle as a function of input datum 104 and actualangle of aircraft in the aforementioned attitudes. Attitude error 204may include measurements as detected by one or more sensors configuredto measure aircraft angle like an IMU, gyroscope, motion sensor, opticalsensor, a combination thereof, or another sensor of combination ofsensors. Outer loop controller 200 may include clipped moment 208 as aninput to controller. Clipped moment 208 may include one or more elementsof data that have been selected from a larger sample size or range.Clipped moment 208 may have been selected for its lack of noise,improved efficiency, or accuracy of moment associated with any one ormore elements of an electric aircraft consistent with the entirety ofthis disclosure. Gain may be a linear operation. Gain compression may benot linear and, as such, its effect may be one of distortion, due to thenonlinearity of the transfer characteristic which also causes a loss of‘slope’ or ‘differential’ gain. So, the output may be less than expectedusing the small signal gain of the amplifier. In clipping, the signalmay be abruptly limited to a certain amplitude and may be therebydistorted in keeping under that level. This creates extra harmonics thatare not present in the original signal. “Soft” clipping or limitingmeans there isn't a sharp “knee point” in the transfer characteristic. Asine wave that has been softly clipped will become more like a squarewave with more rounded edges, but will still have many extra harmonics.Outer loop controller 200 may include Kp operational amplifier 212. Kpop amp 212 may include one or more constants configured to scale any oneor more signals in any control loop or otherwise computing devices foruse in controlling aspects of an electric aircraft. Outer loopcontroller 200 may include integral decoy logic 216. Outer loopcontroller 200 may include integrator 220. Integrator 220 may include anoperational amplifier configured to perform a mathematical operation ofintegration of a signal; output voltage may be proportional to inputvoltage integrated over time. An input current may be offset by anegative feedback current flowing in the capacitor, which may begenerated by an increase in output voltage of the amplifier. The outputvoltage may be therefore dependent on the value of input current it hasto offset and the inverse of the value of the feedback capacitor. Thegreater the capacitor value, the less output voltage has to be generatedto produce a particular feedback current flow. The input impedance ofthe circuit may be almost zero because of the Miller effect. Hence allthe stray capacitances (the cable capacitance, the amplifier inputcapacitance, etc.) are virtually grounded and they have no influence onthe output signal. Operational amplifier as used in integrator may beused as part of a positive or negative feedback amplifier or as an adderor subtractor type circuit using just pure resistances in both the inputand the feedback loop. As its name implies, the Op-amp Integrator is anoperational amplifier circuit that causes the output to respond tochanges in the input voltage over time as the op-amp produces an outputvoltage which may be proportional to the integral of the input voltage.In other words, the magnitude of the output signal may be determined bythe length of time a voltage may be present at its input as the currentthrough the feedback loop charges or discharges the capacitor as therequired negative feedback occurs through the capacitor. Input voltagemay be Vin and represent the input signal to controller such as one ormore of input datum 104 and/or attitude error 204. Output voltage Voutmay represent output voltage such as one or more outputs like ratesetpoint 232. When a step voltage, Vin may be firstly applied to theinput of an integrating amplifier, the uncharged capacitor C has verylittle resistance and acts a bit like a short circuit allowing maximumcurrent to flow via the input resistor, Rin as potential differenceexists between the two plates. No current flows into the amplifiersinput and point X may be a virtual earth resulting in zero output. Asthe impedance of the capacitor at this point may be very low, the gainratio of X_(C)/R_(IN) may be also very small giving an overall voltagegain of less than one, (voltage follower circuit). As the feedbackcapacitor, C begins to charge up due to the influence of the inputvoltage, its impedance Xc slowly increase in proportion to its rate ofcharge. The capacitor charges up at a rate determined by the RC timeconstant, (τ) of the series RC network. Negative feedback forces theop-amp to produce an output voltage that maintains a virtual earth atthe op-amp's inverting input. Since the capacitor may be connectedbetween the op-amp's inverting input (which may be at virtual groundpotential) and the op-amp's output (which may be now negative), thepotential voltage, Vc developed across the capacitor slowly increasescausing the charging current to decrease as the impedance of thecapacitor increases. This results in the ratio of Xc/Rin increasingproducing a linearly increasing ramp output voltage that continues toincrease until the capacitor may be fully charged. At this point thecapacitor acts as an open circuit, blocking any more flow of DC current.The ratio of feedback capacitor to input resistor (X_(C)/R_(IN)) may benow infinite resulting in infinite gain. The result of this high gain(similar to the op-amps open-loop gain), may be that the output of theamplifier goes into saturation as shown below. (Saturation occurs whenthe output voltage of the amplifier swings heavily to one voltage supplyrail or the other with little or no control in between). The rate atwhich the output voltage increases (the rate of change) may bedetermined by the value of the resistor and the capacitor, “RC timeconstant”. By changing this RC time constant value, either by changingthe value of the Capacitor, C or the Resistor, R, the time in which ittakes the output voltage to reach saturation can also be changed forexample. Outer loop controller 200 may include a double integrator,consistent with the description of an integrator with the entirety ofthis disclosure. Single or double integrators consistent with theentirety of this disclosure may include analog or digital circuitcomponents. Outer loop controller 200 may include Ki operationalamplifier 224. Ki op amp 224 may be a unique constant configured toscale any one or more signals or data as described herein with referenceto kp op amp 212. Outer loop controller 200 may include large amplitudegain reduction 228. Large amplitude gain reduction 228 may be configuredto reduce gain on large amplitude input signals consistent with theabove description. Compression of gain may be caused by non-linearcharacteristics of the device when run at large amplitudes. With anysignal, as the input level may be increased beyond the linear range ofthe amplifier, gain compression will occur. A transistor's operatingpoint may move with temperature, so higher power output may lead tocompression due to collector dissipation. But it may be not a change ingain; it may be non-linear distortion. The output level stays relativelythe same as the input level goes higher. Once the non-linear portion ofthe transfer characteristic of any amplifier may be reached, anyincrease in input will not be matched by a proportional increase inoutput. Thus, there may be compression of gain. Also, at this timebecause the transfer function may be no longer linear, harmonicdistortion will result. In intentional compression (sometimes calledautomatic gain control or audio level compression as used in devicescalled ‘dynamic range compressors’, the overall gain of the circuit maybe actively changed in response to the level of the input over time, sothe transfer function remains linear over a short period of time. A sinewave into such a system will still look like a sine wave at the output,but the overall gain may be varied, depending on the level of that sinewave. Above a certain input level, the output sine wave will always bethe same amplitude. The output level of Intentional compression variesover time, in order to minimize non-linear behavior. With gaincompression, the opposite may be true, its output may be constant. Inthis respect intentional compression serves less of an artistic purpose.

Referring now to FIG. 3 , an exemplary embodiment of inner loopcontroller 300 is presented in block diagram form. Inner loop controller300 may include clipped moment 308 as an input to controller. Gain maybe a linear operation. Gain compression may be not linear and, as such,its effect may be one of distortion, due to the nonlinearity of thetransfer characteristic which also causes a loss of ‘slope’ or‘differential’ gain. So, the output may be less than expected using thesmall signal gain of the amplifier. In clipping, the signal may beabruptly limited to a certain amplitude and may be thereby distorted inkeeping under that level. This creates extra harmonics that are notpresent in the original signal. “Soft” clipping or limiting means thereisn't a sharp “knee point” in the transfer characteristic. A sine wavethat has been softly clipped will become more like a square wave withmore rounded edges but will still have many extra harmonics. Inner loopcontroller 300 may include Kp operational amplifier 312. Inner loopcontroller 300 may include integral decoy logic 316. Inner loopcontroller 300 may include integrator 320. Integrator 320 may include anoperational amplifier configured to perform a mathematical operation ofintegration of a signal; output voltage may be proportional to inputvoltage integrated over time. An input current may be offset by anegative feedback current flowing in the capacitor, which may begenerated by an increase in output voltage of the amplifier. The outputvoltage may be therefore dependent on the value of input current it hasto offset and the inverse of the value of the feedback capacitor. Thegreater the capacitor value, the less output voltage has to be generatedto produce a particular feedback current flow. The input impedance ofthe circuit almost zero because of the Miller effect. Hence all thestray capacitances (the cable capacitance, the amplifier inputcapacitance, etc.) are virtually grounded and they have no influence onthe output signal. Operational amplifier as used in integrator may beused as part of a positive or negative feedback amplifier or as an adderor subtractor type circuit using just pure resistances in both the inputand the feedback loop. As its name implies, the Op-amp Integrator is anoperational amplifier circuit that causes the output to respond tochanges in the input voltage over time as the op-amp produces an outputvoltage which may be proportional to the integral of the input voltage.In other words, the magnitude of the output signal may be determined bythe length of time a voltage may be present at its input as the currentthrough the feedback loop charges or discharges the capacitor as therequired negative feedback occurs through the capacitor. Input voltagemay be Vin and represent the input signal to controller such as one ormore of input datum 104 and/or attitude error 304. Output voltage Voutmay represent output voltage such as one or more outputs like ratesetpoint 332. When a step voltage, Vin may be firstly applied to theinput of an integrating amplifier, the uncharged capacitor C has verylittle resistance and acts a bit like a short circuit allowing maximumcurrent to flow via the input resistor, Rin as potential differenceexists between the two plates. No current flows into the amplifiersinput and point X may be a virtual earth resulting in zero output. Asthe impedance of the capacitor at this point may be very low, the gainratio of X_(C)/R_(IN) may be also very small giving an overall voltagegain of less than one, (voltage follower circuit). As the feedbackcapacitor, C begins to charge up due to the influence of the inputvoltage, its impedance Xc slowly increase in proportion to its rate ofcharge. The capacitor charges up at a rate determined by the RC timeconstant, (I) of the series RC network. Negative feedback forces theop-amp to produce an output voltage that maintains a virtual earth atthe op-amp's inverting input. Since the capacitor may be connectedbetween the op-amp's inverting input (which may be at virtual groundpotential) and the op-amp's output (which may be now negative), thepotential voltage, Vc developed across the capacitor slowly increasescausing the charging current to decrease as the impedance of thecapacitor increases. This results in the ratio of Xc/Rin increasingproducing a linearly increasing ramp output voltage that continues toincrease until the capacitor may be fully charged. At this point thecapacitor acts as an open circuit, blocking any more flow of DC current.The ratio of feedback capacitor to input resistor (X_(C)/R_(IN)) may benow infinite resulting in infinite gain. The result of this high gain,similar to the op-amps open-loop gain, may be that the output of theamplifier goes into saturation as shown below. (Saturation occurs whenthe output voltage of the amplifier swings heavily to one voltage supplyrail or the other with little or no control in between). The rate atwhich the output voltage increases (the rate of change) may bedetermined by the value of the resistor and the capacitor, “RC timeconstant”. By changing this RC time constant value, either by changingthe value of the Capacitor, C or the Resistor, R, the time in which ittakes the output voltage to reach saturation can also be changed forexample. Inner loop controller 300 may include a double integrator,consistent with the description of an integrator with the entirety ofthis disclosure. Single or double integrators consistent with theentirety of this disclosure may include analog or digital circuitcomponents. Inner loop controller 300 may include Ki operationalamplifier 324. Inner loop controller 300 may include lead-lag filters328 consistent with the description of lead-lag filters herein below.Inner loop controller 300 may include lift lever input 332 as describedherein below. Inner loop controller 300 may include Schedule on liftlever 236 as described herein below.

Inner loop controller 300 may include pitch rate damping. Adding pitchrate damping with the elevators may be the least intrusive form ofaugmentation that has been suggested. In this scheme, the elevator inputmay be a sum of the pilot input (as in fully manual flight) and acomponent that arrests pitch rate as measured by the IMU's such as IMU112. The scheduling on the lift lever may be such that in forward flight(with 0 assisted lift), the full damping may be active. As the liftlever rises above some value (set to 0.1), the damping rolls off so thatvery low airspeed behavior may be handled entirely by the attitudecontroller. The higher this value may be set, the more active theelevator damping will be at low-speed flight (i.e., flight withsubstantial assisted lift). The saturation on the damping term ensuresthat the pilot has some amount of control authority regardless of whatthe augmentation attempts to do. With this design, as with the baselinedesign, there may be no blending between modes required duringacceleration from lift assisted flight to fully wing-borne flight.Additionally, there may be no control discontinuity as the lift fansturn off and stow.

With continued reference to FIG. 3 , an alternative augmentationstrategy may be to close a pitch rate loop with the control surfaces. Ifone chooses to use this, note that in order to avoid blending betweencontrol modes while accelerating from low-speed flight to wing-borneflight, the control system commanding the lift rotors must also be RCRH(as opposed to the nominal ACAH). An RCRH low airspeed controllerpotentially increases pilot workload substantially. Also note that thegains appropriate for this controller change substantially across anelectric aircraft's range of cruise airspeeds (as elevator effectivitychanges with dynamic pressure). Since the lift lever will be all the waydown during cruise, lift lever can no longer use this signal as a proxyfor airspeed. Since using airspeed as an input would introduce anadditional low reliability system, the system would be forced to selectconstant gains that produce a stable system at all reasonable airspeeds.The resulting system would have poor performance at low airspeeds. Itmay be possible to approximate airspeed in cruise from knowledge of thepusher performance and the operating speed and torque. Such an estimateof airspeed would likely be sufficient to enable the scheduling of gainson airspeed, which would result in less conservative design, and higherperformance. For the purposes of controlling a vehicle, the flightcontrol system 100 are interested in the aerodynamic forces that thelift rotors can provide. However, since the aerodynamic forces andtorques that the rotors generate are a function of speed, and the liftrotors have substantial inertia, simply passing the corresponding steadystate torque commands to the motor will result in a slow thrustresponse. If this substantial phase lag may be not compensated for,performance will be severely limited. Because the flight control system100 have a good understanding of the physics involved, the flightcontrol system 100 can apply a dynamic inverse of the rotor model to thesteady state torque signals in order to obtain better speed tracking,and therefore better thrust tracking. Intuitively, this dynamic inverseadds a “kick” forward when the incoming signal increases sharply andadds a “kick” backwards when the incoming signal decreases sharply. Thismay be very much the same as how the flight control system 100accelerate a car to highway speed. Once the car may be at speed, onelikely only needs one quarter throttle to maintain speed, which suggeststhat holding one quarter throttle for a sufficiently long time startingfrom a low speed would eventually accelerate the car to the desiredspeed. Of course, if one uses full throttle to get up to speed, and thenreturns to quarter throttle to hold speed, a faster response can beachieved. This may be the core idea of what the dynamic inverse does. Toapply a dynamic inverse, the flight control system 100 first generate amodel based on Euler's equation in 1 dimension. Here, I may be the faninertia about the axis of rotation, \omega may be the angular velocityof the motor, \tau_{motor} may be the shaft torque generated by themotor, and \tau_{aero} may be the aerodynamic shaft torque. Because theaerodynamic term may be nonlinear in the speed state, the flight controlsystem 100 will omit this from the dynamic inversion for simplicity andhandle it separately. Eventually, the torque command that the flightcontrol system 100 send to the motor will be a sum of a softened dynamicinverse of the motor inertia, and an approximation of the aerodynamictorque as below. First, the flight control system 100 will determine thevalue of the inertia dynamic inverse term. When the flight controlsystem 100 inverts the inertia-only model (i.e. obtain the output→inputresponse rather than the input→output response), the flight controlsystem 100 will end up with a pure derivative, which has an infinitehigh frequency response, and may be thus not desirable. However, if theflight control system 100 passed a desired speed through this transferfunction (given below), the resulting torque output would perfectlyreproduce the desired speed. To make this work on a real system withtorque limits, the flight control system 100 will add a first order lowpass filter in series with the dynamic inverse sI. If the motors hadunlimited torque capability, the resulting dynamics from input to motorspeed would be just the low pass dynamics. Note that a motor speedcommand may be present in this expression. However, the flight controlsystem 100 would like to avoid closing a speed loop on the lift motors.The decision to not close a speed loop was made on the belief that thethrust-torque relationship was more constant than the thrust-speedrelationship for edgewise flight. This may be not the case; bothrelationships vary similarly with edgewise airspeed according to DUSTsimulations. This decision may be re-evaluated in the future. However,because speed may be the only state of the system, the flight controlsystem 100 may be forced to generate some speed as input to this filter.Note that this speed does not have to be particularly accurate—there areno loops being closed on it, and this dynamic inverse decays to 0quickly after the input signal stops changing. An appropriate means togenerate this pseudo-reference speed may be to use the well-knownapproximation for the static speed-torque relationship for a fan: Usingthis relationship, the flight control system 100 can compute theapproximate steady state speed that corresponds to a given torque input.Then, this speed signal may be passed through the dynamic inverse of theinertia only system. If this was the only torque that was applied to thelift motors in a vacuum (i.e., no aero drag), the lift rotors wouldtrack speeds reasonably well. Of course, this may be not the case, andthe flight control system 100 must still account for the aerodynamictorque. If the flight control system 100 could always apply the exactaerodynamic torque experienced by the fan (but in the opposite sense)with the motor, any additional input would “see” only the inertia of thefan and motor. If this additional input may be the inertia-only dynamicinverse, then the flight control system 100 would obtain the desiredfirst order low pass response in speed. Consider the followingnon-limiting example of bootstrapping. If the flight control system 100assumes that the flight control system 100 has a good approximation ofaerodynamic torque and motor saturation does not engage, then the motorspeed response (and therefore the aero torque, approximately) will be afirst order low pass filter, with time constant \tau_{ff}. This tells usthat the flight control system 100 can approximate the aerodynamictorque by passing the steady state torque command through a similarfirst order transfer function. The combination of this filtered steadystate torque and dynamic inversion of the approximated correspondingspeed may be shown below. To implement this in discrete time, thetransfer functions are discretized using the Tustin, or Bilineartransform. Setting \tau_{ff} and \tau_{fwd} involves simulation of thesystem subject to different size and direction of input changes aboutdifferent operating points. These time constants are tweaked to make thefans spin up as quickly as possible over a range of inputs. Intuitively,an excessively large time constant results in a slow response. However,a very short time constant also results in a slow response. With a veryshort time constant, the amplitude of the initial kick from the dynamicinverse may be very large, but also very short in duration. As a resultof motor saturation, the total achieved energy increase from the kickmay be low. An intermediate value of time constant (set to approximately0.13) provides a faster response than either extreme. Due to the natureof the dynamic inverse, this system amplifies noise in the steady statetorque command. To avoid this becoming a nuisance while the aircraft maybe grounded, the dynamic inverse term may be scheduled on the positionof the lift lever in the same way as the inner loop gains, but with alower threshold. That may be, for 0 lift lever input, there may be 0dynamic inversion contribution. This contribution ramps up linearly tofull at 5% lift lever input. This inertia compensation (or somethingfunctionally similar), which may be essentially a lead-lag filter, butwith physically derived pole and zero locations, may be essential to thehigh-performance operation of any vehicle with slow control actuators.Without this, the phase lag introduced by the actuators makes itimpossible to achieve bandwidth sufficient for satisfactory handlingqualities. For well-flown transitions, the lift lever position may be agood proxy for airspeed, which directly determines the effectiveness ofthe conventional control surfaces. This follows from the fact that at afixed angle of attack, dynamic pressure on the wing and unpowered liftare linearly related. Therefore, in order to maintain altitude (which apilot would tend to do), one would need to lower the lift lever asairspeed increases. In the case that a pilot were to rapidly pull up onthe lift lever not in accordance with a decrease in airspeed, a pilot'scontrol inputs would produce more than nominal control moment on thevehicle due to lift fan gains not being scheduled down and high dynamicpressure. In simulation, this scenario has been shown to benon-catastrophic, although it will likely be somewhat violent as thevehicle accelerates upwards rapidly and experiences some attitudetransients. It may be easy to understand that each motor can only outputa torque between some lower limit and some upper limit. If the flightcontrol system 100 draw the area that corresponds to these availablemotor commands for the 2-fan system, the flight control system 100 findthat a “box” may be formed. If the flight control system 100 assume alinear torque-thrust relationship, then so long as the motors do notrotate on the body, the map from this acceptable box in the motor torquespace to the acceptable box in the space where the axes are vehiclelevel upward thrust and torque may be linear. Therefore, the shape canonly be scaled, flipped, and rotated, but straight edges remainstraight, and the number of vertices cannot change. With thistransformation done, the flight control system 100 can now readilydetermine if a particular commanded force and torque combination may bepossible to achieve. Suppose that the flight control system 100 choosesto prioritize vehicle level torque over force. In the case that theforce and torque combination may be inside the box, no saturationoccurs—the mixer may be able to achieve the request, and noprioritization may be needed. Suppose instead that some points with thedesired torque are within the box, but none of these points have thedesired force. Algorithmically, the flight control system 100 first getthe achieved torque to match the desired torque as closely as possible.Then, that value may be locked down, and then subject to thatconstraint, the flight control system 100 matches the desired thrust asclosely as possible. In this case, the desired torque is achieved, butthe desired thrust is not. Mathematically, this is two sequentiallysolved linear programs (linear objective, linear constraints). Becausethe flight control system 100 knew the map from motor torques to vehicletorques, and because that map is invertible, the flight control system100 can now apply the inverse of this map to get a motor torque command148 from the point the flight control system 100 identified in thevehicle torque space. Since the point is inside the box in the vehicletorque space, it is guaranteed to also be inside the box in the motortorque vector space, and thus guarantees that the resulting torquecommands will be within the limits of the motors. Note that the flightcontrol system 100 have not only resolved the motor saturation, theflight control system 100 also know how much force and torque the flightcontrol system 100 are trying to produce (i.e. the flight control system100 haven't blindly done some clipping/rescaling of the motor signals).While this example uses only two dimensions, the principle may be thesame in higher dimensions. The solution method used may be slightlydifferent than what may be shown here, but the concept may be the same.Finally, it is important to note that throughout this process, theflight control system 100 has assumed that torque corresponds to thrust.This may be only true in the case of steady state operation. Because thelift fans or one or other propulsors take a substantial amount of timeto spin up, this assumption may be not necessarily accurate. As aresult, the mixer's estimate of achieved moment may be not accurate forrapidly changing inputs without inertia compensation. the flight controlsystem 100 can use a behavioral model of the lift fans or speed feedbackto better approximate the true moment acting on the aircraft due topowered lift.

Referring now to FIG. 4 , a method for flight control configured for usein electric aircraft includes, at 405, capturing, at an at least asensor 104, an input datum 108 from a pilot. At least a sensor may beconsistent with any sensor as described herein. The input datum may beconsistent with any input datum as described herein. At least a sensor104 may be mechanically and communicatively connected to a throttle. Thethrottle may be consistent with any throttle as described herein. Atleast a sensor 104 may be mechanically and communicatively connected toan inceptor stick. The inceptor stick may be consistent with anyinceptor stick as described herein. At least a sensor may bemechanically and communicatively connected to at least a foot pedal. Thefoot pedal may be consistent with any foot pedal as described herein.

Still referring to FIG. 4 , at 410, includes detecting, at the inertialmeasurement unit 112, at least an aircraft angle 116. The inertialmeasurement unit 112 may be consistent with any inertial measurementunit as described herein. At least an aircraft angle 116 may beconsistent with any aircraft angle as described herein.

Still referring to FIG. 4 , at 415, includes detecting, at the inertialmeasurement unit 412, at least an aircraft angle rate 420. At least anaircraft angle rate 420 may be consistent with any aircraft angle rateas described herein.

Still referring to FIG. 4 , at 420, includes receiving, at the outerloop controller 128, at least an input datum 108 from at least a sensor104. The outer loop controller 128 may be consistent with any outer loopcontroller as described herein. The input datum 108 may be consistentwith any input datum as described herein. At least a sensor 104 may beconsistent with any sensor as described herein. The flight controllermay be implemented using a processor. The flight controller 124 may beconsistent with any flight controller as described herein. The processormay be consistent with any processor as described herein.

Still referring to FIG. 4 , at 425, includes receiving, at the outerloop controller 128, at least an aircraft angle 116 from the inertialmeasurement unit 112. The outer loop controller may be consistent withany outer loop controller as described herein. At least an aircraftangle 116 may be consistent with any aircraft angle as described herein.

Still referring to FIG. 4 , at 430, includes generating, at the outerloop controller 128, a rate setpoint 132 as a function of at least aninput datum 108. The outer loop controller may be any outer loopcontroller as described herein. The rate setpoint may be any ratesetpoint as described herein. The input datum may be consistent with anyinput data as described herein.

Still referring to FIG. 4 , at 435, includes receiving, at the innerloop controller 136, at least an aircraft angle rate 120 from theinertial measurement unit 112. The inner loop controller 136 may beconsistent with any inner loop controller as described herein. The innerloop controller may include a lead-lag filter. The inner loop controllermay include an integrator. At least an aircraft angle rate 120 may beany aircraft angle rate as described herein. The inertial measurementunit 112 may be consistent with any inertial measurement unit asdescribed herein.

Still referring to FIG. 4 , at 440, includes receiving, at the innerloop controller 136, the rate setpoint 132 from the outer loopcontroller 128. The inner loop controller 136 may be consistent with anyinner loop controller as described herein. The rate setpoint 132 may beconsistent with any rate setpoint as described herein. The outer loopcontroller 128 may be described herein.

Still referring to FIG. 4 , at 445, includes receiving, at the innerloop controller 128, a moment datum 140 as a function of the ratesetpoint. The inner loop controller 128 may be consistent with any innerloop controller as described herein. The moment datum 140 may consistentwith any moment datum as described herein.

Still referring to FIG. 4 , at 450, includes receiving, at the mixer144, the moment datum 140. The mixer 144 may be consistent with anymixer as described herein. The moment datum 140 may be consistent withany moment datum as described herein. The mixer 144 may be implementedusing an electrical logic circuit. The mixer may include an inertiacompensator.

Still referring to FIG. 4 , at 455, includes performing, at the mixer144, a torque allocation as a function of the moment datum 140. Themixer 144 may be consistent with any mixer as described herein. Themoment datum 140 may be consistent with any moment datum as describedherein.

Still referring to FIG. 4 , at 460, includes generating, at the mixer144, at least a motor torque command datum 148 as a function of thetorque allocation. The mixer 144 may be consistent with any mixer asdescribed herein. The motor torque command datum 148 may be consistentwith any motor command datum as described herein. The motor torquecommand datum 148 may be transmitted to a plurality of flightcomponents. The motor torque command datum 148 may be consistent withany motor torque command datum as described herein. The flightcomponents may be consistent with any flight components as describedherein.

Referring now to FIG. 5 , flight controller 124, outer loop controller128, inner loop controller 136 or another computing device or model thatmay utilize stored data to generate any datum as described herein.Stored data may be past inconsistency datums, predictive datums,measured state datums, or the like in an embodiment of the presentinvention. Stored data may be input by a user, pilot, support personnel,or another. Stored data may include algorithms and machine-learningprocesses that may generate one or more datums associated with theherein disclosed system including input datums, moment datums, and thelike. The algorithms and machine-learning processes may be any algorithmor machine-learning processes as described herein. Training data may becolumns, matrices, rows, blocks, spreadsheets, books, or other suitabledatastores or structures that contain correlations between past inputsdatums, moment datums, or the like to motor torque commands. Trainingdata may be any training data as described below. Training data may bepast measurements detected by any sensors described herein or anothersensor or suite of sensors in combination. Training data may be detectedby onboard or offboard instrumentation designed to detect measured statedatum or environmental conditions as described herein. Training data maybe uploaded, downloaded, and/or retrieved from a server prior to flight.Training data may be generated by a computing device that may simulateinput datums suitable for use by the flight controller, controller, orother computing devices in an embodiment of the present invention.Flight controller, controller, and/or another computing device asdescribed in this disclosure may train one or more machine-learningmodels using the training data as described in this disclosure. Trainingone or more machine-learning models consistent with the training one ormore machine learning modules as described in this disclosure.

With continued reference to FIG. 5 , algorithms and machine-learningprocesses may include any algorithms or machine-learning processes asdescribed herein. Training data may be columns, matrices, rows, blocks,spreadsheets, books, or other suitable datastores or structures thatcontain correlations between torque measurements to obstruction datums.Training data may be any training data as described herein. Trainingdata may be past measurements detected by any sensors described hereinor another sensor or suite of sensors in combination. Training data maybe detected by onboard or offboard instrumentation designed to detectenvironmental conditions and measured state datums as described herein.Training data may be uploaded, downloaded, and/or retrieved from aserver prior to flight. Training data may be generated by a computingdevice that may simulate predictive datums, performance datums, or thelike suitable for use by the flight controller, controller, plant model,in an embodiment of the present invention. Flight controller,controller, and/or another computing device as described in thisdisclosure may train one or more machine-learning models using thetraining data as described in this disclosure.

Still referring to FIG. 5 , an exemplary embodiment of amachine-learning module 500 that may perform one or moremachine-learning processes as described in this disclosure may beillustrated. Machine-learning module may perform determinations,classification, and/or analysis steps, methods, processes, or the likeas described in this disclosure using machine learning processes. A“machine learning process,” as used in this disclosure, may be a processthat automatedly uses training data 504 to generate an algorithm thatwill be performed by a computing device/module to produce outputs 508given data provided as inputs 512; this may be in contrast to anon-machine learning software program where the commands to be executedare determined in advance by a user and written in a programminglanguage.

Still referring to FIG. 5 , “training data,” as used herein, may be datacontaining correlations that a machine-learning process may use to modelrelationships between two or more categories of data elements. Forinstance, and without limitation, training data 504 may include aplurality of data entries, each entry representing a set of dataelements that were recorded, received, and/or generated together; dataelements may be correlated by shared existence in a given data entry, byproximity in a given data entry, or the like. Multiple data entries intraining data 504 may evince one or more trends in correlations betweencategories of data elements; for instance, and without limitation, ahigher value of a first data element belonging to a first category ofdata element may tend to correlate to a higher value of a second dataelement belonging to a second category of data element, indicating apossible proportional or other mathematical relationship linking valuesbelonging to the two categories. Multiple categories of data elementsmay be related in training data 504 according to various correlations;correlations may indicate causative and/or predictive links betweencategories of data elements, which may be modeled as relationships suchas mathematical relationships by machine-learning processes as describedin further detail below. Training data 504 may be formatted and/ororganized by categories of data elements, for instance by associatingdata elements with one or more descriptors corresponding to categoriesof data elements. As a non-limiting example, training data 504 mayinclude data entered in standardized forms by persons or processes, suchthat entry of a given data element in a given field in a form may bemapped to one or more descriptors of categories. Elements in trainingdata 504 may be linked to descriptors of categories by tags, tokens, orother data elements; for instance, and without limitation, training data504 may be provided in fixed-length formats, formats linking positionsof data to categories such as comma-separated value (CSV) formats and/orself-describing formats such as extensible markup language (XML),JavaScript Object Notation (JSON), or the like, enabling processes ordevices to detect categories of data.

Alternatively, or additionally, and continuing to refer to FIG. 5 ,training data 504 may include one or more elements that are notcategorized; that may be, training data 504 may not be formatted orcontain descriptors for some elements of data. Machine-learningalgorithms and/or other processes may sort training data 504 accordingto one or more categorizations using, for instance, natural languageprocessing algorithms, tokenization, detection of correlated values inraw data and the like; categories may be generated using correlationand/or other processing algorithms. As a non-limiting example, in acorpus of text, phrases making up a number “n” of compound words, suchas nouns modified by other nouns, may be identified according to astatistically significant prevalence of n-grams containing such words ina particular order; such an n-gram may be categorized as an element oflanguage such as a “word” to be tracked similarly to single words,generating a new category as a result of statistical analysis.Similarly, in a data entry including some textual data, a person's namemay be identified by reference to a list, dictionary, or othercompendium of terms, permitting ad-hoc categorization bymachine-learning algorithms, and/or automated association of data in thedata entry with descriptors or into a given format. The ability tocategorize data entries automatedly may enable the same training data504 to be made applicable for two or more distinct machine-learningalgorithms as described in further detail below. Training data 504 usedby machine-learning module 500 may correlate any input data as describedin this disclosure to any output data as described in this disclosure.As a non-limiting illustrative example at least an input datum 108 andmoment datum 140 may be inputs, wherein motor torque command 148 may beoutputted.

Further referring to FIG. 5 , training data may be filtered, sorted,and/or selected using one or more supervised and/or unsupervisedmachine-learning processes and/or models as described in further detailbelow; such models may include without limitation a training dataclassifier 516. Training data classifier 516 may include a “classifier,”which as used in this disclosure may be a machine-learning model asdefined below, such as a mathematical model, neural net, or programgenerated by a machine learning algorithm known as a “classificationalgorithm,” as described in further detail below, that sorts inputs intocategories or bins of data, outputting the categories or bins of dataand/or labels associated therewith. A classifier may be configured tooutput at least a datum that labels or otherwise identifies a set ofdata that are clustered together, found to be close under a distancemetric as described below, or the like. Machine-learning module 500 maygenerate a classifier using a classification algorithm, defined as aprocesses whereby a computing device and/or any module and/or componentoperating thereon derives a classifier from training data 504.Classification may be performed using, without limitation, linearclassifiers such as without limitation logistic regression and/or naiveBayes classifiers, nearest neighbor classifiers such as k-nearestneighbors classifiers, support vector machines, least squares supportvector machines, fisher's linear discriminant, quadratic classifiers,decision trees, boosted trees, random forest classifiers, learningvector quantization, and/or neural network-based classifiers. As anon-limiting example, training data classifier 516 may classify elementsof training data to classes of deficiencies, wherein a nourishmentdeficiency may be categorized to a large deficiency, a mediumdeficiency, and/or a small deficiency.

Still referring to FIG. 5 , machine-learning module 500 may beconfigured to perform a lazy-learning process 520 and/or protocol, whichmay alternatively be referred to as a “lazy loading” or“call-when-needed” process and/or protocol, may be a process wherebymachine learning may be conducted upon receipt of an input to beconverted to an output, by combining the input and training set toderive the algorithm to be used to produce the output on demand. Forinstance, an initial set of simulations may be performed to cover aninitial heuristic and/or “first guess” at an output and/or relationship.As a non-limiting example, an initial heuristic may include a ranking ofassociations between inputs and elements of training data 504. Heuristicmay include selecting some number of highest-ranking associations and/ortraining data 504 elements. Lazy learning may implement any suitablelazy learning algorithm, including without limitation a K-nearestneighbors algorithm, a lazy naïve Bayes algorithm, or the like; personsskilled in the art, upon reviewing the entirety of this disclosure, willbe aware of various lazy-learning algorithms that may be applied togenerate outputs as described in this disclosure, including withoutlimitation lazy learning applications of machine-learning algorithms asdescribed in further detail below.

Alternatively or additionally, and with continued reference to FIG. 5 ,machine-learning processes as described in this disclosure may be usedto generate machine-learning models 524. A “machine-learning model,” asused in this disclosure, may be a mathematical and/or algorithmicrepresentation of a relationship between inputs and outputs, asgenerated using any machine-learning process including withoutlimitation any process as described above, and stored in memory; aninput is submitted to a machine-learning model 524 once created, whichgenerates an output based on the relationship that was derived. Forinstance, and without limitation, a linear regression model, generatedusing a linear regression algorithm, may compute a linear combination ofinput data using coefficients derived during machine-learning processesto calculate an output datum. As a further non-limiting example, amachine-learning model 524 may be generated by creating an artificialneural network, such as a convolutional neural network comprising aninput layer of nodes, one or more intermediate layers, and an outputlayer of nodes. Connections between nodes may be created via the processof “training” the network, in which elements from a training data 504set are applied to the input nodes, a suitable training algorithm (suchas Levenberg-Marquardt, conjugate gradient, simulated annealing, orother algorithms) is then used to adjust the connections and weightsbetween nodes in adjacent layers of the neural network to produce thedesired values at the output nodes. This process may be sometimesreferred to as deep learning.

Still referring to FIG. 5 , machine-learning algorithms may include atleast a supervised machine-learning process 528. At least a supervisedmachine-learning process 528, as defined herein, include algorithms thatreceive a training set relating a number of inputs to a number ofoutputs, and seek to find one or more mathematical relations relatinginputs to outputs, where each of the one or more mathematical relationsmay be optimal according to some criterion specified to the algorithmusing some scoring function. For instance, a supervised learningalgorithm may include input datum 108 as described above as one or moreinputs, moment datum 140 as an output, and a scoring functionrepresenting a desired form of relationship to be detected betweeninputs and outputs; scoring function may, for instance, seek to maximizethe probability that a given input and/or combination of elements inputsmay be associated with a given output to minimize the probability that agiven input may be not associated with a given output. Scoring functionmay be expressed as a risk function representing an “expected loss” ofan algorithm relating inputs to outputs, where loss is computed as anerror function representing a degree to which a prediction generated bythe relation may be incorrect when compared to a given input-output pairprovided in training data 504. Persons skilled in the art, uponreviewing the entirety of this disclosure, will be aware of variouspossible variations of at least a supervised machine-learning process528 that may be used to determine relation between inputs and outputs.Supervised machine-learning processes may include classificationalgorithms as defined above.

Further referring to FIG. 5 , machine learning processes may include atleast an unsupervised machine-learning processes 532. An unsupervisedmachine-learning process, as used herein, is a process that derivesinferences in datasets without regard to labels; as a result, anunsupervised machine-learning process may be free to discover anystructure, relationship, and/or correlation provided in the data.Unsupervised processes may not require a response variable; unsupervisedprocesses may be used to find interesting patterns and/or inferencesbetween variables, to determine a degree of correlation between two ormore variables, or the like.

Still referring to FIG. 5 , machine-learning module 500 may be designedand configured to create a machine-learning model 524 using techniquesfor development of linear regression models. Linear regression modelsmay include ordinary least squares regression, which aims to minimizethe square of the difference between predicted outcomes and actualoutcomes according to an appropriate norm for measuring such adifference (e.g. a vector-space distance norm); coefficients of theresulting linear equation may be modified to improve minimization.Linear regression models may include ridge regression methods, where thefunction to be minimized includes the least-squares function plus termmultiplying the square of each coefficient by a scalar amount topenalize large coefficients. Linear regression models may include leastabsolute shrinkage and selection operator (LASSO) models, in which ridgeregression may be combined with multiplying the least-squares term by afactor of 1 divided by double the number of samples. Linear regressionmodels may include a multi-task lasso model wherein the norm applied inthe least-squares term of the lasso model may be the Frobenius normamounting to the square root of the sum of squares of all terms. Linearregression models may include the elastic net model, a multi-taskelastic net model, a least angle regression model, a LARS lasso model,an orthogonal matching pursuit model, a Bayesian regression model, alogistic regression model, a stochastic gradient descent model, aperceptron model, a passive aggressive algorithm, a robustnessregression model, a Huber regression model, or any other suitable modelthat may occur to persons skilled in the art upon reviewing the entiretyof this disclosure. Linear regression models may be generalized in anembodiment to polynomial regression models, whereby a polynomialequation (e.g. a quadratic, cubic or higher-order equation) providing abest predicted output/actual output fit may be sought; similar methodsto those described above may be applied to minimize error functions, aswill be apparent to persons skilled in the art upon reviewing theentirety of this disclosure.

Continuing to refer to FIG. 5 , machine-learning algorithms may include,without limitation, linear discriminant analysis. Machine-learningalgorithm may include quadratic discriminate analysis. Machine-learningalgorithms may include kernel ridge regression. Machine-learningalgorithms may include support vector machines, including withoutlimitation support vector classification-based regression processes.Machine-learning algorithms may include stochastic gradient descentalgorithms, including classification and regression algorithms based onstochastic gradient descent. Machine-learning algorithms may includenearest neighbors algorithms. Machine-learning algorithms may includeGaussian processes such as Gaussian Process Regression. Machine-learningalgorithms may include cross-decomposition algorithms, including partialleast squares and/or canonical correlation analysis. Machine-learningalgorithms may include naïve Bayes methods. Machine-learning algorithmsmay include algorithms based on decision trees, such as decision treeclassification or regression algorithms. Machine-learning algorithms mayinclude ensemble methods such as bagging meta-estimator, forest ofrandomized tress, AdaBoost, gradient tree boosting, and/or votingclassifier methods. Machine-learning algorithms may include neural netalgorithms, including convolutional neural net processes.

Referring now to FIG. 6 , an embodiment of an electric aircraft 600 ispresented. Still referring to FIG. 6 , electric aircraft 600 may includea vertical takeoff and landing aircraft (eVTOL). As used herein, avertical take-off and landing (eVTOL) aircraft may be one that canhover, take off, and land vertically. An eVTOL, as used herein, may bean electrically powered aircraft typically using an energy source, of aplurality of energy sources to power the aircraft. In order to optimizethe power and energy necessary to propel the aircraft. eVTOL may becapable of rotor-based cruising flight, rotor-based takeoff, rotor-basedlanding, fixed-wing cruising flight, airplane-style takeoff,airplane-style landing, and/or any combination thereof. Rotor-basedflight, as described herein, may be where the aircraft generated liftand propulsion by way of one or more powered rotors connected with anengine, such as a “quad copter,” multi-rotor helicopter, or othervehicle that maintains its lift primarily using downward thrustingpropulsors. Fixed-wing flight, as described herein, may be where theaircraft may be capable of flight using wings and/or foils that generatelife caused by the aircraft's forward airspeed and the shape of thewings and/or foils, such as airplane-style flight. Control forces of theaircraft are achieved by conventional elevators, ailerons and ruddersduring fixed wing flight. Roll and Pitch control forces on the aircraftare achieved during transition flight by increasing and decreasingtorque, and thus thrust on the four lift fans. Increasing torque on bothleft motors and decreasing torque on both right motors leads to a rightroll, for instance. Likewise, increasing the torque on the front motorsand decreasing the torque on the rear motors leads to a nose up pitchingmoment. Clockwise and counterclockwise turning motors torques areincreased and decreased to achieve the opposite torque on the overallaircraft about the vertical axis and achieve yaw maneuverability.

With continued reference to FIG. 6 , a number of aerodynamic forces mayact upon the electric aircraft 600 during flight. Forces acting on anelectric aircraft 600 during flight may include, without limitation,thrust, the forward force produced by the rotating element of theelectric aircraft 600 and acts parallel to the longitudinal axis.Another force acting upon electric aircraft 600 may be, withoutlimitation, drag, which may be defined as a rearward retarding forcewhich may be caused by disruption of airflow by any protruding surfaceof the electric aircraft 600 such as, without limitation, the wing,rotor, and fuselage. Drag may oppose thrust and acts rearward parallelto the relative wind. A further force acting upon electric aircraft 600may include, without limitation, weight, which may include a combinedload of the electric aircraft 600 itself, crew, baggage, and/or fuel.Weight may pull electric aircraft 600 downward due to the force ofgravity. An additional force acting on electric aircraft 600 mayinclude, without limitation, lift, which may act to oppose the downwardforce of weight and may be produced by the dynamic effect of air actingon the airfoil and/or downward thrust from the propulsor of the electricaircraft. Lift generated by the airfoil may depend on speed of airflow,density of air, total area of an airfoil and/or segment thereof, and/oran angle of attack between air and the airfoil. For example, and withoutlimitation, electric aircraft 600 are designed to be as lightweight aspossible. Reducing the weight of the aircraft and designing to reducethe number of components may be essential to optimize the weight. Tosave energy, it may be useful to reduce weight of components of anelectric aircraft 600, including without limitation propulsors and/orpropulsion assemblies. In an embodiment, the motor may eliminate needfor many external structural features that otherwise might be needed tojoin one component to another component. The motor may also increaseenergy efficiency by enabling a lower physical propulsor profile,reducing drag and/or wind resistance. This may also increase durabilityby lessening the extent to which drag and/or wind resistance add toforces acting on electric aircraft 600 and/or propulsors.

Referring still to FIG. 6 , Aircraft may include at least a verticalpropulsor 604 and at least a forward propulsor 608. A forward propulsormay be a propulsor that propels the aircraft in a forward direction.Forward in this context may be not an indication of the propulsorposition on the aircraft; one or more propulsors mounted on the front,on the wings, at the rear, etc. A vertical propulsor may be a propulsorthat propels the aircraft in a upward direction; one of more verticalpropulsors may be mounted on the front, on the wings, at the rear,and/or any suitable location. A propulsor, as used herein, may be acomponent or device used to propel a craft by exerting force on a fluidmedium, which may include a gaseous medium such as air or a liquidmedium such as water. At least a vertical propulsor 604 may be apropulsor that generates a substantially downward thrust, tending topropel an aircraft in a vertical direction providing thrust formaneuvers such as without limitation, vertical take-off, verticallanding, hovering, and/or rotor-based flight such as “quadcopter” orsimilar styles of flight.

With continued reference to FIG. 6 , at least a forward propulsor 608 asused in this disclosure may be a propulsor positioned for propelling anaircraft in a “forward” direction; at least a forward propulsor mayinclude one or more propulsors mounted on the front, on the wings, atthe rear, or a combination of any such positions. At least a forwardpropulsor may propel an aircraft forward for fixed-wing and/or“airplane”-style flight, takeoff, and/or landing, and/or may propel theaircraft forward or backward on the ground. At least a verticalpropulsor 604 and at least a forward propulsor 608 includes a thrustelement. At least a thrust element may include any device or componentthat converts the mechanical energy of a motor, for instance in the formof rotational motion of a shaft, into thrust in a fluid medium. At leasta thrust element may include, without limitation, a device using movingor rotating foils, including without limitation one or more rotors, anairscrew or propeller, a set of airscrews or propellers such ascontrarotating propellers, a moving or flapping wing, or the like. Atleast a thrust element may include without limitation a marine propelleror screw, an impeller, a turbine, a pump-jet, a paddle or paddle-baseddevice, or the like. As another non-limiting example, at least a thrustelement may include an eight-bladed pusher propeller, such as aneight-bladed propeller mounted behind the engine to ensure the driveshaft may be in compression. Propulsors may include at least a motormechanically connected to at least a first propulsor as a source ofthrust. A motor may include without limitation, any electric motor,where an electric motor may be a device that converts electrical energyinto mechanical energy, for instance by causing a shaft to rotate. Atleast a motor may be driven by direct current (DC) electric power; forinstance, at least a first motor may include a brushed DC at least afirst motor, or the like. At least a first motor may be driven byelectric power having varying or reversing voltage levels, such asalternating current (AC) power as produced by an alternating currentgenerator and/or inverter, or otherwise varying power, such as producedby a switching power source. At least a first motor may include, withoutlimitation, brushless DC electric motors, permanent magnet synchronousat least a first motor, switched reluctance motors, or induction motors.In addition to inverter and/or a switching power source, a circuitdriving at least a first motor may include electronic speed controllersor other components for regulating motor speed, rotation direction,and/or dynamic braking. Persons skilled in the art, upon reviewing theentirety of this disclosure, will be aware of various devices that maybe used as at least a thrust element.

With continued reference to FIG. 6 , during flight, a number of forcesmay act upon the electric aircraft. Forces acting on an aircraft 600during flight may include thrust, the forward force produced by therotating element of the aircraft 600 and acts parallel to thelongitudinal axis. Drag may be defined as a rearward retarding forcewhich may be caused by disruption of airflow by any protruding surfaceof the aircraft 600 such as, without limitation, the wing, rotor, andfuselage. Drag may oppose thrust and acts rearward parallel to therelative wind. Another force acting on aircraft 600 may include weight,which may include a combined load of the aircraft 600 itself, crew,baggage and fuel. Weight may pull aircraft 600 downward due to the forceof gravity. An additional force acting on aircraft 600 may include lift,which may act to oppose the downward force of weight and may be producedby the dynamic effect of air acting on the airfoil and/or downwardthrust from at least a propulsor. Lift generated by the airfoil maydepends on speed of airflow, density of air, total area of an airfoiland/or segment thereof, and/or an angle of attack between air and theairfoil.

With continued reference to FIG. 6 , at least a portion of an electricaircraft may include at least a propulsor. A propulsor, as used herein,may be a component or device used to propel a craft by exerting force ona fluid medium, which may include a gaseous medium such as air or aliquid medium such as water. In an embodiment, when a propulsor twistsand pulls air behind it, it will, at the same time, push an aircraftforward with an equal amount of force. The more air pulled behind anaircraft, the greater the force with which the aircraft may be pushedforward. Propulsor may include any device or component that consumeselectrical power on demand to propel an electric aircraft in a directionor other vehicle while on ground or in-flight.

With continued reference to FIG. 6 , in an embodiment, at least aportion of the aircraft may include a propulsor, the propulsor mayinclude a propeller, a blade, or any combination of the two. Thefunction of a propeller may be to convert rotary motion from an engineor other power source into a swirling slipstream which pushes thepropeller forwards or backwards. The propulsor may include a rotatingpower-driven hub, to which are attached several radial airfoil-sectionblades such that the whole assembly rotates about a longitudinal axis.The blade pitch of the propellers may, for example, be fixed, manuallyvariable to a few set positions, automatically variable (e.g. a“constant-speed” type), or any combination thereof. In an embodiment,propellers for an aircraft are designed to be fixed to their hub at anangle similar to the thread on a screw makes an angle to the shaft; thisangle may be referred to as a pitch or pitch angle which will determinethe speed of the forward movement as the blade rotates.

With continued reference to FIG. 6 , in an embodiment, a propulsor caninclude a thrust element which may be integrated into the propulsor. Thethrust element may include, without limitation, a device using moving orrotating foils, such as one or more rotors, an airscrew or propeller, aset of airscrews or propellers such as contra-rotating propellers, amoving or flapping wing, or the like. Further, a thrust element, forexample, can include without limitation a marine propeller or screw, animpeller, a turbine, a pump-jet, a paddle or paddle-based device, or thelike.

It is to be noted that any one or more of the aspects and embodimentsdescribed herein may be conveniently implemented using one or moremachines (e.g., one or more computing devices that are utilized as auser computing device for an electronic document, one or more serverdevices, such as a document server, etc.) programmed according to theteachings of the present specification, as will be apparent to those ofordinary skill in the computer art. Appropriate software coding canreadily be prepared by skilled programmers based on the teachings of thepresent disclosure, as will be apparent to those of ordinary skill inthe software art. Aspects and implementations discussed above employingsoftware and/or software modules may also include appropriate hardwarefor assisting in the implementation of the machine executableinstructions of the software and/or software module.

It is to be noted that any one or more of the aspects and embodimentsdescribed herein may be conveniently implemented using one or moremachines (e.g., one or more computing devices that are utilized as auser computing device for an electronic document, one or more serverdevices, such as a document server, etc.) programmed according to theteachings of the present specification, as will be apparent to those ofordinary skill in the computer art. Appropriate software coding canreadily be prepared by skilled programmers based on the teachings of thepresent disclosure, as will be apparent to those of ordinary skill inthe software art. Aspects and implementations discussed above employingsoftware and/or software modules may also include appropriate hardwarefor assisting in the implementation of the machine executableinstructions of the software and/or software module.

Such software may be a computer program product that employs amachine-readable storage medium. A machine-readable storage medium maybe any medium that is capable of storing and/or encoding a sequence ofinstructions for execution by a machine (e.g., a computing device) andthat causes the machine to perform any one of the methodologies and/orembodiments described herein. Examples of a machine-readable storagemedium include, but are not limited to, a magnetic disk, an optical disc(e.g., CD, CD-R, DVD, DVD-R, etc.), a magneto-optical disk, a read-onlymemory “ROM” device, a random access memory “RAM” device, a magneticcard, an optical card, a solid-state memory device, an EPROM, an EEPROM,and any combinations thereof. A machine-readable medium, as used herein,is intended to include a single medium as well as a collection ofphysically separate media, such as, for example, a collection of compactdiscs or one or more hard disk drives in combination with a computermemory. As used herein, a machine-readable storage medium does notinclude transitory forms of signal transmission.

Such software may also include information (e.g., data) carried as adata signal on a data carrier, such as a carrier wave. For example,machine-executable information may be included as a data-carrying signalembodied in a data carrier in which the signal encodes a sequence ofinstruction, or portion thereof, for execution by a machine (e.g., acomputing device) and any related information (e.g., data structures anddata) that causes the machine to perform any one of the methodologiesand/or embodiments described herein.

Examples of a computing device include, but are not limited to, anelectronic book reading device, a computer workstation, a terminalcomputer, a server computer, a handheld device (e.g., a tablet computer,a smartphone, etc.), a web appliance, a network router, a networkswitch, a network bridge, any machine capable of executing a sequence ofinstructions that specify an action to be taken by that machine, and anycombinations thereof. In one example, a computing device may includeand/or be included in a kiosk.

FIG. 7 shows a diagrammatic representation of one embodiment of acomputing device in the exemplary form of a computer system 700 withinwhich a set of instructions for causing a control system to perform anyone or more of the aspects and/or methodologies of the presentdisclosure may be executed. It is also contemplated that multiplecomputing devices may be utilized to implement a specially configuredset of instructions for causing one or more of the devices to performany one or more of the aspects and/or methodologies of the presentdisclosure. Computer system 700 includes a processor 704 and a memory708 that communicate with each other, and with other components, via abus 712. Bus 712 may include any of several types of bus structuresincluding, but not limited to, a memory bus, a memory controller, aperipheral bus, a local bus, and any combinations thereof, using any ofa variety of bus architectures.

Processor 704 may include any suitable processor, such as withoutlimitation a processor incorporating logical circuitry for performingarithmetic and logical operations, such as an arithmetic and logic unit(ALU), which may be regulated with a state machine and directed byoperational inputs from memory and/or sensors; processor 704 may beorganized according to Von Neumann and/or Harvard architecture as anon-limiting example. Processor 704 may include, incorporate, and/or beincorporated in, without limitation, a microcontroller, microprocessor,digital signal processor (DSP), Field Programmable Gate Array (FPGA),Complex Programmable Logic Device (CPLD), Graphical Processing Unit(GPU), general purpose GPU, Tensor Processing Unit (TPU), analog ormixed signal processor, Trusted Platform Module (TPM), a floating pointunit (FPU), and/or system on a chip (SoC).

Memory 708 may include various components (e.g., machine-readable media)including, but not limited to, a random-access memory component, a readonly component, and any combinations thereof. In one example, a basicinput/output system 716 (BIOS), including basic routines that help totransfer information between elements within computer system 700, suchas during start-up, may be stored in memory 708. Memory 708 may alsoinclude (e.g., stored on one or more machine-readable media)instructions (e.g., software) 720 embodying any one or more of theaspects and/or methodologies of the present disclosure. In anotherexample, memory 708 may further include any number of program modulesincluding, but not limited to, an operating system, one or moreapplication programs, other program modules, program data, and anycombinations thereof.

Computer system 700 may also include a storage device 724. Examples of astorage device (e.g., storage device 724) include, but are not limitedto, a hard disk drive, a magnetic disk drive, an optical disc drive incombination with an optical medium, a solid-state memory device, and anycombinations thereof. Storage device 724 may be connected to bus 712 byan appropriate interface (not shown). Example interfaces include, butare not limited to, SCSI, advanced technology attachment (ATA), serialATA, universal serial bus (USB), IEEE 1394 (FIREWIRE), and anycombinations thereof. In one example, storage device 724 (or one or morecomponents thereof) may be removably interfaced with computer system 700(e.g., via an external port connector (not shown)). Particularly,storage device 724 and an associated machine-readable medium 728 mayprovide nonvolatile and/or volatile storage of machine-readableinstructions, data structures, program modules, and/or other data forcomputer system 700. In one example, software 720 may reside, completelyor partially, within machine-readable medium 728. In another example,software 720 may reside, completely or partially, within processor 704.

Computer system 700 may also include an input device 732. In oneexample, a user of computer system 700 may enter commands and/or otherinformation into computer system 700 via input device 732. Examples ofan input device 732 include, but are not limited to, an alpha-numericinput device (e.g., a keyboard), a pointing device, a joystick, agamepad, an audio input device (e.g., a microphone, a voice responsesystem, etc.), a cursor control device (e.g., a mouse), a touchpad, anoptical scanner, a video capture device (e.g., a still camera, a videocamera), a touchscreen, and any combinations thereof. Input device 732may be interfaced to bus 712 via any of a variety of interfaces (notshown) including, but not limited to, a serial interface, a parallelinterface, a game port, a USB interface, a FIREWIRE interface, a directinterface to bus 712, and any combinations thereof. Input device 732 mayinclude a touch screen interface that may be a part of or separate fromdisplay 736, discussed further below. Input device 732 may be utilizedas a user selection device for selecting one or more graphicalrepresentations in a graphical interface as described above.

A user may also input commands and/or other information to computersystem 700 via storage device 724 (e.g., a removable disk drive, a flashdrive, etc.) and/or network interface device 740. A network interfacedevice, such as network interface device 740, may be utilized forconnecting computer system 700 to one or more of a variety of networks,such as network 744, and one or more remote devices 748 connectedthereto. Examples of a network interface device include, but are notlimited to, a network interface card (e.g., a mobile network interfacecard, a LAN card), a modem, and any combination thereof. Examples of anetwork include, but are not limited to, a wide area network (e.g., theInternet, an enterprise network), a local area network (e.g., a networkassociated with an office, a building, a campus or other relativelysmall geographic space), a telephone network, a data network associatedwith a telephone/voice provider (e.g., a mobile communications providerdata and/or voice network), a direct connection between two computingdevices, and any combinations thereof. A network, such as network 744,may employ a wired and/or a wireless mode of communication. In general,any network topology may be used. Information (e.g., data, software 720,etc.) may be communicated to and/or from computer system 700 via networkinterface device 740.

Computer system 700 may further include a video display adapter 752 forcommunicating a displayable image to a display device, such as displaydevice 736. Examples of a display device include, but are not limitedto, a liquid crystal display (LCD), a cathode ray tube (CRT), a plasmadisplay, a light emitting diode (LED) display, and any combinationsthereof. Display adapter 752 and display device 736 may be utilized incombination with processor 704 to provide graphical representations ofaspects of the present disclosure. In addition to a display device,computer system 700 may include one or more other peripheral outputdevices including, but not limited to, an audio speaker, a printer, andany combinations thereof. Such peripheral output devices may beconnected to bus 712 via a peripheral interface 756. Examples of aperipheral interface include, but are not limited to, a serial port, aUSB connection, a FIREWIRE connection, a parallel connection, and anycombinations thereof.

The foregoing has been a detailed description of illustrativeembodiments of the invention. Various modifications and additions can bemade without departing from the spirit and scope of this invention.Features of each of the various embodiments described above may becombined with features of other described embodiments as appropriate inorder to provide a multiplicity of feature combinations in associatednew embodiments. Furthermore, while the foregoing describes a number ofseparate embodiments, what has been described herein is merelyillustrative of the application of the principles of the presentinvention. Additionally, although particular methods herein may beillustrated and/or described as being performed in a specific order, theordering is highly variable within ordinary skill to achieve methods,systems, and software according to the present disclosure. Accordingly,this description is meant to be taken only by way of example, and not tootherwise limit the scope of this invention.

Exemplary embodiments have been disclosed above and illustrated in theaccompanying drawings. It will be understood by those skilled in the artthat various changes, omissions and additions may be made to that whichis specifically disclosed herein without departing from the spirit andscope of the present invention.

What is claimed is:
 1. A system for flight control configured for use inan electric aircraft, the system comprising: at least a sensor, the atleast a sensor configured to capture at least an input datum from apilot; an inertial measurement unit, the inertial measurement unitconfigured to: detect at least an aircraft angle; and detect at least anaircraft angle rate; a flight controller, the flight controllercomprising: an outer loop controller, the outer loop controllerconfigured to: receive the at least an input datum from the at least asensor; receive the at least an aircraft angle from the inertialmeasurement unit; and generate a rate setpoint as a function of the atleast an input datum; an inner loop controller, the inner loopcontroller configured to: receive the at least an aircraft angle rate;receive the rate setpoint from the outer loop controller; and generate amoment datum as a function of the rate setpoint; and a mixer, the mixerconfigured to: receive the moment datum; map vehicle level controltorques, received from the inner loop controller, to actuator output;solve at least an optimization problem; perform a torque allocation as afunction of the moment datum and at least an optimization problem, thetorque allocation comprising a first torque to a first propulsor and asecond torque to a second propulsor; and generate at least a motorcommand datum as a function of the torque allocation.
 2. The system ofclaim 1, wherein at least a sensor is mechanically and communicativelyconnected to a throttle.
 3. The system of claim 1, wherein at least asensor is mechanically and communicatively connected to an inceptorstick.
 4. The system of claim 1, wherein at least a sensor ismechanically and communicatively connected to at least a foot pedal. 5.The system of claim 1, wherein the flight controller further comprises aprocessor.
 6. The system of claim 1, wherein the mixer further comprisesa logic circuit.
 7. The system of claim 1, wherein the mixer furthercomprises an inertia compensator.
 8. The system of claim 1, wherein theinner loop controller further comprises a lead-lag filter.
 9. The systemof claim 1, wherein the inner loop controller further comprises anintegrator.
 10. The system of claim 1, wherein the motor torque commandis transmitted to a plurality of flight components.
 11. A method offlight control configured for use in electric aircraft, the methodcomprising: capturing, at an at least a sensor, an at least an inputdatum from a pilot; detecting, at the inertial measurement unit, atleast an aircraft angle; detecting, at the inertial measurement unit, atleast an aircraft angle rate; receiving, at the outer loop controller,at least an input datum from the at least a sensor; receiving, at theouter loop controller, the at least an aircraft angle from the inertialmeasurement unit; generating, at the outer loop controller, a ratesetpoint as a function of the at least an input datum; receiving, at theinner loop controller, the at least an aircraft angle rate from theinertial measurement unit; receiving, at the inner loop controller, therate setpoint from the outer loop controller; generating, at the innerloop controller, a moment datum as a function of the rate setpoint;receiving, at a mixer, the moment datum; mapping vehicle level controltorques, received from the inner loop controller, to actuator output;solving, at a mixer, at least an optimization problem; performing, atthe mixer, a torque allocation as a function of the moment datum and atleast an optimization problem, the torque allocation comprising a firsttorque to a first propulsor and a second torque to a second propulsor;and generating, at the mixer, at least a motor command datum as afunction of the torque allocation.
 12. The method of claim 11, whereinat least a sensor is mechanically and communicatively connected to athrottle.
 13. The method of claim 11, wherein at least a sensor ismechanically and communicatively connected to an inceptor stick.
 14. Themethod of claim 11, wherein at least a sensor is mechanically andcommunicatively connected to at least a foot pedal.
 15. The method ofclaim 11, wherein the flight controller is implemented using aprocessor.
 16. The method of claim 11, wherein the mixer is implementedusing an electrical logic circuit.
 17. The method of claim 11, whereinthe mixer comprises an inertia compensator.
 18. The method of claim 11,wherein the inner loop controller comprises a lead-lag filter.
 19. Themethod of claim 1, wherein the inner loop controller comprises anintegrator.
 20. The method of claim 11, wherein the motor torque commandis transmitted to a plurality of flight components.